structures de poisson logarithmiques: invariants

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HAL Id: tel-00985181 https://tel.archives-ouvertes.fr/tel-00985181 Submitted on 29 Apr 2014 HAL is a multi-disciplinary open access archive for the deposit and dissemination of sci- entific research documents, whether they are pub- lished or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Structures de Poisson Logarithmiques: invariants cohomologiques et préquantification Joseph Dongho To cite this version: Joseph Dongho. Structures de Poisson Logarithmiques: invariants cohomologiques et préquantifica- tion. Analyse classique [math.CA]. Université d’Angers, 2012. Français. tel-00985181

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Page 1: Structures de Poisson logarithmiques: invariants

HAL Id: tel-00985181https://tel.archives-ouvertes.fr/tel-00985181

Submitted on 29 Apr 2014

HAL is a multi-disciplinary open accessarchive for the deposit and dissemination of sci-entific research documents, whether they are pub-lished or not. The documents may come fromteaching and research institutions in France orabroad, or from public or private research centers.

L’archive ouverte pluridisciplinaire HAL, estdestinée au dépôt et à la diffusion de documentsscientifiques de niveau recherche, publiés ou non,émanant des établissements d’enseignement et derecherche français ou étrangers, des laboratoirespublics ou privés.

Structures de Poisson Logarithmiques : invariantscohomologiques et préquantification

Joseph Dongho

To cite this version:Joseph Dongho. Structures de Poisson Logarithmiques : invariants cohomologiques et préquantifica-tion. Analyse classique [math.CA]. Université d’Angers, 2012. Français. tel-00985181

Page 2: Structures de Poisson logarithmiques: invariants

♥♥é

♦rr

❯❱

♦ ♦t♦r ❯

ès ♦t♦rt ❯♥rsté ♥rs

♥t♦♥ té♠tqs

Prés♥té ♣r

♦s♣ ♦♥♦

♥r à

à ❯♥rsté ♥rs à ♥rs

trtrs P♦ss♦♥ ♦rt♠qs ♥r♥ts♦♦♠♦♦qs t ♣réq♥tt♦♥

r②

♣♣♦rtrs

r♠♥♦ r Pr♦ssr ♥ss r③ rr♦ Pr♦ssr ❯

①♠♥trs

♥ ♦♠s Pr♦ssr ♥rs♥ r♥r Pr♦ssr ♥rs

è ♦ ♦②♦♠ Pr♦ssr ♦♥t♣r

rtr ès ❱♦♦② ♦ts♦ Pr♦ssr ♥rs♦♥rr t♦♥ ♦♠♦ Pr♦ssr ❯♥ ❨♦♥é

é♣rt♠♥t té♠tqs ❯♥rsté ♥rs ❯

♦r ♦sr ①

Page 3: Structures de Poisson logarithmiques: invariants
Page 4: Structures de Poisson logarithmiques: invariants

➒ ♥♦tê ♠ á♠

Page 5: Structures de Poisson logarithmiques: invariants

♠r♠♥ts

r♠r s Pr♦ssrs ♥ ♦♠s t t♦♥ ♦♠♦ q

♦♥t éé ♠♦♥ ♥térêt ♣♦r ♦♠♥ t♦♣♦♦ érq t ♠♦♥t t

♦♥♥îtr ♦rt♦r ♥♥ r ♥ té♠tqs ♦ù

tt tès été té é♠r à é♠r

♦t ♠ rtt Pr♦ssr ❱♦♦② ♦ts♦ q ♠

♦rt♦r t ♣té ♥rr ♠s tr① P♥♥t t♦t tt ♣ér♦

é♥éé s ♦♥t♥ tt♥t♦♥ qté ss ①♣t♦♥s t ss

ss ♦♥ss sés s rr s ♣r♦è♠s réés ♣r st♥ t ♦ssé

♥♠érq q ♥♦s sé♣rt q♥ éts ♠r♦♥ ♥éstt ♣s à ♠

♦♥r ♣r téé♣♦♥ q♥ ss ♠s rst♥t s♥s ré♣♦♥s ê♠ ss ♠s

t ss ♥s ♥s s s ❯r♥♥s t ss ♥ ♠♣ê♥t ♣s

r ♠s ♣r♦ts ♠ s♦♥s q ♣r ♣s ♥ ♦s t ♦é r ♥

❯r♥ à ♦s♦ ♣♦r ♠ ♦♥ttr t ré♣♦♥r à ♠s qst♦♥s

été étr♠♥♥t ♥s tr ♥ tr♦ ♥ t qt ♥ r♥çs

♣♦♥t ♠ ♣r♠ttr ①♣r♠r q rss♥t ♣r♦♦♥ ♠♦ ♥ s♦♥ st

♦t t ♣r ♠r à r♥r ♥t♣ ss q

r t ♠① q q ♦♥q r ♣r q st q r♣rés♥t

♣♦r ♠♦ ♥ r♠r s♥èr♠♥t

P♦r r r♠r é♠♥t t♦s s ♠♠rs ♦rt♦r

q ôt♦②és q♦t♥♥♠♥t r à ♦r ❳ ♠s

❨ ♦♥ ❯ r♥ç♦s ❱ r♥t

❯ r♥r réér ♥P♣♣ ♥

❯ ♥ ❱ s ❩❨ P♦tr ❯ ♦ ❯

♦ï ❲ ♦♣ ♦♦♣ ♥qs

❯❯ ést♥ P❯ s♥ ❱❱

r ❯ P♣♣ ♦

♠♠ ❨ è ❨❱ éè♥ q ♦♥t

♦♥♥é ♣♦t♥t à ♠ tr ♠té♠tq à trrs rs rs ①♣♦sés

r♠r ♣rtèr♠♥t s Pr♦ssrs ♥qs ♦r

t♦r t ❯ ♦ï rtr ♦♥t ♣♦r t♦ts s

tés ♠♥strts t r ♥ ♥s trt♠♥t ♠s ♦ssrs rs

srs étr♥♠♥t r♦♥♥ss♥t

r♠r

s srétrs ♦rt♦r t ♥♦s ♦térs s ❯

tr♥ ❯❩ ①♥r Ptt♦r♣s r♥ç♦s r♦♥

s rtrs é♣rt♠♥t P♣♣ ❯ ♥ ❯ t

r♥ç♦s ❯

s rtrs ♦rt♦r ♥ ♠ P❯

t ♥q

Page 6: Structures de Poisson logarithmiques: invariants

♥é♥r s②stè♠ q♥

r♠r ♣rtèr♠♥t ♥ q ♣♣r♦ ♥ é♠

r ♠♦♥ ♥sr♣t♦♥ ♥ tès ♦rt♦r t q ♠ré ss ♦♣t♦♥s

tr♦t t♦♦rs ♥ t♠♣s ♣♦r ♣♣♦rtr s ①♣t♦♥s sr s ♣♦♥ts ♦♠r

♣r♦① rt t♦ st rsté r♥t t♦t t♠♣s tt♥t à ♠s

qst♦♥s s ♣r♥t ♣r♦s ss ♦t♦♥s q♦t♥♥s ♣♦r tr♦r s

ré♣♦♥ss à ♠s ♥s ♥♦rs ♠s s♦♥ ♠ érr ♥s

q ♠ tr♥s♠t ❱♦♦② s s♦t♦♥s à ♠s ♣r♦è♠s ♥ ♥r

sqs t ♦t♥ ♣rès ♥ ss ♦♦rtrs ♥ s♣♥ ♦♥ r

♠étt t♦♦rs ♦rt s♦t ♦♦r ♦ù à s à é ♠é♦tt t

♠♣♣♦rtt s ①♣t♦♥s ♥éssrs ♠rr ♠ ♠♥r s ♥st ♣s

♠♦♥ tr rtr tès ss ♦ r♠ttr ♥t♣

r♠r ♥♥ ♦r ♣té êtr ♠♠r r② tt tès

r♠r é♠♥t Pr♦ssr è ♦ ♦②♦♠ q ♣t ♠♦♥

tt♥t♦♥ ♥rs é♦♠étr à trrs s♦♥ ♥♦ ①♣♦sé sr ❱èr à

①è♠ r♥♦♥tr r♦♣ ♦♣♦♦ t é♦♠étr rq ♥tr à

❯♥rsté s♥ ♥ é♠r ê♠ ♠ t t♦s ♠s ♣r♦ts

t ♠ tr♥s♠s ♥ ♣rès ♥ s ♦rrt♦♥s ♥éssrs r♠r ♣♦r

s♦♥ ♥tt♦♥ t q ♠ résré ♦♠r à ❯

❯ P ♥ ♣r♦t

♣♦r r♠rr t♦s s ♠♠rs ♦rt♦r ♣♦r r r♥t

♦rt sé♦r r♠r ♥♥ ♦r ♣té r ♣rt s ♠♠rs r②

r♠r Pr♦ssr r♠♥♦ r ♣♦r ♥térêt q ♣♦rté à s

tr① t ♣♦r ♦r ♣té tâ r♣♣♦rtr ss ♣rtèr♠♥t

r♦♥♥ss♥t ♣♦r ss ①♣t♦♥s st s s♦t♦♥s ♣tqs s éqt♦♥s

P râ à r♦s ♦r ♦♠♣rs s ♥♦t♦♥s rétés rr t

rêt♠♥t t♥♥t ♥♦rs ♠s ♥♦s sss♦♥ ss ♦

s r♥r ♥t♣

r③♦ Pr♦s♦r s r③ r♦ ♣♦r ss tr♦s ♠út♣s s♦r ♦s

s♦rs rs ② ♣r r ♣t♦ ♣sr ♦s ♣③♦s r♦s trr st

tss s rs sñ♦r Pr♦s♦r

r♠r é♠♥t ♦tr ♥ P♣ r ♦♠é♦ ♣♦r s♦♥ à

♥rs ♥ ss ♠t♣s ♦♣s s t ♠s s ♥♦r♠♥ts ♠t♣s

♠♦♥t été ♥ ♠♣♦rt♥ ♣t ♥s tr

r♠r ♠s ♠rs ♦t♦r♥ts ①♥r ❯

♠r ❯ ③③ ❯ ♦♠♥ é♠ é♠ ♥

①② r ♦♣ ❨ ♥sts ② ❯ ♦♠s③

r♥ P ♥r② P❯ ❯ ❨ ❲ ❳

♦♥ r ❨ s ♦♥t s ♠♦♠♣♥é t♦t ♦♥

Page 7: Structures de Poisson logarithmiques: invariants

s r♥èrs ♥♥és r♠r ♣rtèr♠♥t ①♥r

P❯ t ③♥♥ st♦♥ ♣♦r ♠♦r é à ♦rrr t①t r♠r

Pstr st♦♥ ♦r② ♥♥tt sr ♦ t t♦s s rèrs s

♥éq ♣♦r r s♦t♥ s♥s t rs ♠t♣s ♣rèrs r♠r

ss ♠s ♥♥s ♦ès ②é ❨♦♦ ♣♦r r s♦t♥ t ♥♦r♠♥ts

♣♥s ♣rtèr♠♥t à ♦ ♦rt♥ ♦♠s ♦♥ ♠

r r♠r ♣r♦♦♥é♠♥t rèr ♦♥♦ ♦s♣ t ♦r tt ♣♦r

r ♣rèrs t é♥ét♦♥s

s tr① ♥r♥t ♠s ♦ts s♥s ❯ ss

♠♥ ♠ ♣r♦♥♥r ♣♦r t♦s ♠s ér♠♥ts s ♦♦♥té s♦♠♣ss

à t♦s s âs t ♥ t♦t t♠♣s

r♠r s ♦r♥strs ♣r♦t ♣♦r r s♦t♥ s♥s

t♥s à r♠rr ♣rtèr♠♥t r ♥P♦rt ♥ès ♦♠③

♥♥ t ② ❱♥♥t ♣♦r rs ♠t♣s ♥tr♥t♦♥s r♥t s tr①

r♠r t♦s s ♣rs♦♥♥s ♠ss r♥ ♠r♦♥ ♣♦r s

♠t♣s s ♦rés

t♥s é♠♥t à ①♣r♠r ♠s r♠r♠♥ts ♥rs s trs ♠r♦

❯ ❯♥rsté ❨♦♥é r ♥ ♦ ❯♥rsté

r♦ ♣♦r rs s♦t♥s ♦♥t♥s r♠r Pr♦ssrs ♦ ss

rtr ♦ ♦r♠ ♣érr r♦ ♦tr ♦r♠♥

é♣rt♠♥t té♠tqs r♦ Pr♦ssr

r♥ç♦s ❲♠♦♥ ♦ ♦rrt ♦t♠ é♣rt♠♥t

té♠tqs ❯♥rsté ❨♦♥é ♦tr ♠ t t♦s

s ♠♠rs é♣rt♠♥t té♠tqs ❯♥rsté ❨♦♥é

r♠r ♠s ♦ès ①s rt ♦r r r♥♥ Prr ♦ t

t♦s s ♣rs♦♥♥s r♦

r ss à ♥♥ ♦ ♦♥ ♠ t♥r é♣♦s ♣♦r s ♥♥és

sr tt tès ♥♥ ♦♠é ssé ♣r ss r♠s ♥♦tr♥s

r♠r ss ♠♦♥ ♦♥ ③♠ ♥r t s♦♥ é♣♦s ♣♦r r ♥tt♦♥

à ♦s s♦r r♠r ♥♥ ♠♥ ♥♥ ♠♠♦ t P♣ ♦s♣

♠♦ ♣♦r r ♣rèrs ♦♥t♥s ♣♥s s♥s ss à ♠ é♥t r♥ ♠èr

q ♠♥ s♥s ss à ♠ ♦rr ♦♥r t q ♠♣♣rs ♣t♥

t ♣r♦♥

r♠r ♣rtèr♠♥t P♣ ♥ st♥ ♣♦r t♦t s♦♥ s♦t♥ t ss

♥♦♠r① ♥♦r♠♥ts ♦♠♠ttrs ♥ ♣éé ♠♣r♦♥♥ s ♦s

♠♠♥ tt t P♣ ♦♠ss ts ss q ss ♣ssé ♥♣rç

s r♥èrs ♥♥és s ♦♠♣r♥r♦♥t ♥♠♥t ♣♦rq♦ ♥s ①

♥ srs r♥ ♥♦rs ♣s à ♦r♥♥ t ♠♠♥ ③♥♥ r

♥ ♣♥sé ♣s ♣♦r r♣♦s q r♠♣ç ♠ é♥t r♥ ♠èr

♠s q ♠rs♠♥t t é ♣r ♥ ♦tr ♥s s ♣r♦♣r s♥

Page 8: Structures de Poisson logarithmiques: invariants

t♦ ♠♠♥ ♠♥ q trr ♥♦s ♥êtrs t s♦t éèr

r ♥ s♦♥r ♥♦ ♠ q s♥s ss ♠♥♦r

t t ♠ ♣r♠ttt rtr♦r t♦♥ ♠ t ♠tr♥ q ♠

♠♥qt ♥ s t♠♣s ♥ ♣ssés à ♥rs s ♣♦r ♠♦ ♣s q♥ ♠èr

t r♠r ♠♦r ♦♥♥é ♥ ♣ ♥s t♦♥ ♦②r ♠ ♦♥♥r s♥s

♦t ♥ ♠♦②♥♥ étr♥sr ts t♦♥s ♥rs ♠♦ ss ♦ très t

é♥r t♦s ① q ♦♥t é t♦qé à ♦tr ♣♦rt râ à ♦s ♠s sé♦rs à ♥rs

♦♥t été ♠ ♠♥s♠ t t♥rss r♠r éé♥ t t ❱♦♦②

♠♦r ♣té ♦♠♠ rèr t ♥♦♥ ♦♠♠ étr♥r ♦s s♦t ♥ ♥r

♠rs t ♦♠é râs ss q r r ♥ ♣r♦r ♠r♦♥s

t ♦♥ ♥ ♣t r♠ssr s ♠♥s ♣ ♥ ♣r♥r s♦é

é♦t s ♣rèr s s ① ♠ t ♥ t ♦r à tt

♠ t♦ts s ♦♥♥s râs q ♠ért ♣r♥ s étrsss ♥ ♠♦♥

♥♥♠é ♣r s♣tr ♠ t sr s s♥trs t♠t① ♥ q

♦ss ♦♠♠ t s ♣r♦♠s à ♥♦s ï① s é♥ét♦♥s ♠♣ts à r rté

r♠r ♥♥ ♠s ♥♥ts ♠♦ ❱rs ♠ts ③♠

r s r♦ ♠ ♦ts♦ t ♦t r ♣♦r rs

♣rèrs s♥s ss à ♠♦♥ ér ♥♦rs ♣s ♠s s♦rs t rèrs ♠♦

r♥st♥ ♦ ttr♥ ♦t ②sé r♥r ♦♥♥

Ps ♠♥ ♦♥t♥ t♥♦ ♠ ♦tt ♥♠ r♥ ♥t

ttr♥ ♣♦r r ♥♦♠r① srs à ♠♦♥ ♥r♦t r ♥ très r♥

♠rt♦♥ à ér ♠s t♥ts à ♦♥ à ③ à ♦

r♠r ♠♦♥ ♦s♥ Pr♦ssr ♠♦ rt Ps t t♦t s ♠ ♣♦r

r s♦t♥ s♥s

Page 9: Structures de Poisson logarithmiques: invariants

s ♠tèrs

♥tr♦t♦♥ é♥ér

st ès

t ès

ts t ♠ét♦s tr

♦♥strt♦♥ ♠♦ s ér♥ts ♦r♠s ♦rt

♠qs

trtrs P♦ss♦♥ ♦rt♠qs t ♦♦♠♦♦ P♦s

s♦♥ ♦rt♠q

Préq♥tt♦♥ ♦rt♠q

s réstts ♣r♥♣①

♦♥strt♦♥ s èrs P♦ss♦♥ ♦rt♠qs

♦♥strt♦♥ ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q t

qqs ①♠♣s

♣♣t♦♥ ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

♦tés

r s ♦r♠s ér♥ts ♦rt♠qs

r s strtrs P♦ss♦♥ ♦rt♠qs t ♥r♥ts ♦

♦♠♦♦qs

Prs♣ts

r s èrs P♦ss♦♥ ♦rt♠qs

r s ♦r♠s ér♥ts ♦rt♠qs

r q♥tt♦♥

r s strtrs P♦ss♦♥ ♦rt♠qs

èrs P♦ss♦♥ ♦rt♠qs

ért♦♥s ♦rt♠qs

ér♥ts ♦r♠s ♦rt♠qs

éré ♣r r♣♣♦rt à ♥ ért♦♥ ♦rt♠q

trtrs èrs P♦ss♦♥ ♦rt♠qs

qs ①♠♣s èrs P♦ss♦♥ ♦rt♠qs

❱rétés P♦ss♦♥ ♦rt♠qs

sr r

❯♥ r♠rq sr s ♦r♠s ér♥ts ♦rt♠qs t

♠♣s trs ♦rt♠qs

é♥t♦♥ t ♣r♠èrs ♣r♦♣rétés

❱rétés ♦s②♠♣tqs

qs ①♠♣s rétés P♦ss♦♥ ♦rt♠qs

s♣ s SU(2) ♠♦♥♦♣ôs ♠♥étqs r

Page 10: Structures de Poisson logarithmiques: invariants

s ♠tèrs

♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

♦♥strt♦♥ érq ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

èrs ♥rt ♦rt♠qs

trtr èr ♥rt sr ΩA(log I) ♥t ♣r♥ strtr P♦ss♦♥ ♦rt♠q ♣r♥♣ ♦♥ I.

♦♥strt♦♥ é♦♠étrq ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

qs strtrs èr ss♦és ① strtrs

P♦ss♦♥ ♦rt♠qs

trtrs èr ♥rt sr ΩX(logD)

①♠♣s s r♦♣s ♦♦♠♦♦s P♦ss♦♥

♦rt♠qs

r♦♣ ♦♦♠♦♦ P♦ss♦♥ ♦rt♠qs s str

trs ♦s②♠♣tqs

♦♦♠♦♦ P♦ss♦♥ t P♦ss♦♥ ♦

rt♠q strtr P♦ss♦♥ x, y = 0, x, z =

0, y, z = xyz sr A = C[x, y, z]

Préq♥tt♦♥ s strtrs P♦ss♦♥

♦rt♠qs

Préq♥tt♦♥ s strtrs ♦s②♠♣tqs

qs ♣r♦♣rétés s strtrs ♦s②♠♣tqs

♦♥♥①♦♥ ♦rt♠q

♥trté s ♦r♠s ♦rt♠qs r♠és

Préq♥tt♦♥ s strtrs P♦ss♦♥ ♦rt♠qs

qs r♠rqs sr ♦♦♠♦♦ s rétés P♦ss♦♥

♦rt♠qs

ss r♥P♦ss♦♥ ♦rt♠q

①♠♣s ♣♣t♦♥s

Préq♥tt♦♥ (C2, π = z1∂z1 ∧ ∂z2)

Préqtt♦♥ CP1 ♠♥ strtr

P♦♥ts ét qqs é♠♦♥strt♦♥s

s ♣♦♥ts s qqs s

s strtr f, g = xyzdf ∧ dg ∧ dpdx ∧ dy ∧ dz

♦♥tr♦♥s q ∂1 ∂0 = 0

♦♥tr♦♥s q ∂2 ∂1 = 0

s strtr P♦ss♦♥ x, y = x.

♦r♣

Page 11: Structures de Poisson logarithmiques: invariants

♣tr

♥tr♦t♦♥ é♥ér

♦♠♠r st ès

t ès

ts t ♠ét♦s tr

♦♥strt♦♥ ♠♦ s ér♥ts ♦r♠s ♦rt

♠qs

trtrs P♦ss♦♥ ♦rt♠qs t ♦♦♠♦♦ P♦s

s♦♥ ♦rt♠q

Préq♥tt♦♥ ♦rt♠q

s réstts ♣r♥♣①

♦♥strt♦♥ s èrs P♦ss♦♥ ♦rt♠qs

♦♥strt♦♥ ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q t

qqs ①♠♣s

♣♣t♦♥ ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

♦tés

r s ♦r♠s ér♥ts ♦rt♠qs

r s strtrs P♦ss♦♥ ♦rt♠qs t ♥r♥ts ♦

♦♠♦♦qs

Prs♣ts

r s èrs P♦ss♦♥ ♦rt♠qs

r s ♦r♠s ér♥ts ♦rt♠qs

r q♥tt♦♥

st ès

♦t X ♥ rété ♦♠♣① ♠♥s♦♥ ♥ n t D ♥ sr rét

X éqt♦♥ h = 0 ♦ù h st r♠ ♥ ♦♥t♦♥ ♦♦♠♦r♣ ♥ ♥♦t OX

s s r♠s ♦♥t♦♥s ♦♦♠♦r♣s sr X. ❯♥ strtr P♦ss♦♥

♦♦♠♦r♣ sr X st ♦♥♥é ♥ r♦t −,− q ss♥ à ♥ ♦♣ (f, g)

r♠s ♦♥t♦♥s ♦♦♠♦r♣s ♥ ♥ ♣♦♥t x X ♥ r♠ f, g ♦♥t♦♥

♦♦♠♦r♣ ♥ x ér♥t s ♣r♦♣rétés s♥ts

• −,− st ♥ér ♥ts②♠étrq

• f, g, h+ g, h, f+ h, f, g = 0 ♥tté ♦

Page 12: Structures de Poisson logarithmiques: invariants

♣tr ♥tr♦t♦♥ é♥ér

• f, gh = f, gh+ f, hg rè ♥③

r♥t ♠ê♠ é♥r ♥ ♠♣ trs q ♦♥ ♣t érr ♥s ♥

s②stè♠ ♦♦r♦♥♥és ♦s

P =1

2

∑1≤i,j≤n

Pij(x)∂

∂xi∧ ∂

∂xj

=∑

1≤i<j≤nPij(x)

∂xi∧ ∂

∂xj Pij = −Pji

t q ér ♥tté ♦

1≤i<j≤n

(Pil∂Pjk∂xl

+ Pjl∂Pki∂xl

+ Pkl∂Pij∂xl

) = 0

♣♦r 1 ≤ i, j, k ≤ n. ♥ é♥t ♦rs r♦t P♦ss♦♥ ♦♦♠♦r♣ ♣r

f, g := 〈P, df ∧ dg〉 =∑

1≤i<j≤n

Pij(x)(∂f

∂xi

∂g

∂xj− ∂g

∂xi

∂f

∂xj).

ts strtrs ♥s♥t ♦r ❬P♦s ❪ ♥ ♦♠♦♠♦r♣s♠ OX

♥ér H : ΩX → DerX(OX) t q H(df)(g) = f, g. H st ♣♣é ♣♣

t♦♥ ♠t♦♥♥♥ ss♦é à P. ♠t♦♥♥ ss♦é à t♦t r♠ ♦♥t♦♥

♦♦♠♦r♣ f rt♠♥t à P st r♠ ♠♣ tr é♥ ♣r

Xf = H(df) =n∑

i=1

xi, f∂

∂xi.

Pr rs ♥ r♠ ♠♣ trs δ st t ♦rt♠q ♦♥ D

♦r ❬t♦ ❪ s δ(h) ∈ hOX . ♥ ♥♦t DerX(logD) s r♠s

♠♣ trs ♦rt♠qs ♦♥ D. ♥ ♠♦♥tr q DerX(logD) st

st ♣♦r r♦t ♠♣ trs

❯♥ strtr P♦ss♦♥ ♦♦♠♦r♣ P sr X sr t ♦rt♠q ♦♥ D

s ♠t♦♥♥ ss♦é à t♦t r♠ ♦♥t♦♥ ♦♦♠♦r♣ f st ♥ st♦♥

DerX(logD). ts strtrs P♦ss♦♥ s♦♥t ♥ é♥érst♦♥ s strtrs

P♦ss♦♥ ♥ts ♣r s strtrs ♦s②♠♣tqs ♦s r♣♣♦♥s q s ♥

♦tr ♠♥s♦♥ X st ♣r ♥ ♦r♠ ♠ér♦♠♦r♣ ω st t ♦s②♠♣

tq sr X s st ♦rt♠q r♠é t ♥♦♥ éé♥éré ♥s s ω st ♥

♦r♠ ♦s②♠♣tq sr X, ♦rs ♣♦r t♦t r♠ ♦♥t♦♥ ♦♦♠♦r♣ f, g,

r♦t

f, g = ω(Xf , Xg)

♦ù iXfω = −df st P♦ss♦♥ ♥ ♣♣ r♦t P♦ss♦♥ ♦s②♠♣tq

s strtrs ♦s②♠♣tqs s♦♥t tsés à s ♥ rss ♥s s réér♥s

❬r ❱rr ❪ ❬♦t♦ ❪ t ❬t♦ ❪

Page 13: Structures de Poisson logarithmiques: invariants

t ès

t ès

♦s ♦ts s♦♥t

• ♥tr♦r s ♥♦t♦♥s èr P♦ss♦♥ t rété P♦ss♦♥ ♦rt♠q

• r♠♣r ♥s ♣r♦sss ♣réq♥t♦♥ s♣ s ♣ss ssqs

♣r ♥ rété P♦ss♦♥ ♦rt♠q

• ♥tr♦r s ♦♦♠♦♦s P♦ss♦♥ ♦rt♠q t s♥ srr ♣♦r

étr ♣réq♥tt♦♥ t②♣ rété

♣♦♥t ♠té♠tq ♣réq♥tr ♥ rté s②♠♣tq (X,ω) st

étr ♥ ♦rrs♣♦♥♥ ϕ ♥tr èr (F(X) ⊂ C∞(X), −,−) s

♦srs ssqs t ♥ s♣ rt H à ♦♥strr ♦ù −,− és♥

strtr P♦ss♦♥ ♥t ♣r ω ♣rès r tt ♦rrs♣♦♥♥ ♦t

stsr s ♣r♦♣rétés s♥ts

ϕ st t

s f st ♥ ♦sr ♦♥st♥t ♦rs ϕ(f) st ♠t♣t♦♥ ♣r f.

[f1, f2] = f3 ♦rs ϕ(f1)ϕ(f2) − ϕ(f2)ϕ(f1) = −ihϕ(f3) ♦ù h és♥ ♦♥

st♥t P♥

tr♠♥t t ϕ ♦t r♥r ♦♠♠tt r♠♠ èrs ♥rt

s♥t

0 // F(X)m // +

1 (Γ(L))σ // DerX // 0

0 // R //

OO

(F(X), ω)

ϕ

OO

// Ham(F(X))

OO

// 0.

♦♥ ♦r ❬❯r♥ ❪

ϕ(as) = ∇v(a)s+ 2iπas

♦ù ∇ és♥ ♦♥♥①♦♥ sr ♥ ré ♥ r♦t ♦♠♣① p : L→ X t +1 (Γ(L))

♠♦ s ♦♣értrs ér♥ts ♦rr ♥érr ♦ é à 1 sr ♠♦ s

st♦♥s L.

ts t ♠ét♦s tr

②♥t ♠♦é ♥tr s s♣s ♣ss ♦♥♥t ♣♣♦rtr s ♠♦

t♦♥s s♦t sr s t♥qs ss s♦t s ♦♥srr t ♠♦r s ♦ts

♦s ♦♣t♦♥s ♣♦r r♥èr ♠ét♦ P♦r ♥♦s ♥tr♦s♦♥s ♥♦t♦♥

♦♦♠♦♦ P♦ss♦♥ ♦rt♠q râ à q ♥♦s ♠sr♦♥s ♦strt♦♥

à ①st♥ H

♦s r♣rtss♦♥s tr ♦♠♠ st

Page 14: Structures de Poisson logarithmiques: invariants

♣tr ♥tr♦t♦♥ é♥ér

♦♥strt♦♥ ♠♦ s ér♥ts ♦r♠s ♦rt♠qs

Prt♥t ♥ é ♣r♦♣r I ♥♥ré ♣r ♥ ♣rt S = u1, ..., up ♥

èr ♦♠♠tt t ♥tr A ♥té 1A ♥♦s ♦♥sér♦♥s A♠♦ ♥

♥ré ♣r ΩA ∪ duiui, i = 1, ..., p, ♦ù ΩA és♥ A♠♦ s ér♥ts

är A. ♦s ♥♦t♦♥s ΩA(log I) t ♣♣♦♥s ♠♦ s ér♥ts

är ♦rt♠qs ♦♥ I. ♦s r♣♣♦♥s q♥ ért♦♥ δ sr Ast t ♦rt♠q ♦♥ I s δ(I) ⊂ I. ♥ és♥ ♣r DerA(log I) A

♠♦ s ért♦♥s ♦rt♠qs ♦♥ I. Pr ♦♥strt♦♥ DerA(log I)st ♥ s♦s èr DerA. ♦s ♦♥sér♦♥s s♦s ♠♦ DerA(log I) DerA(log I) ♦r♠é s δ ts q δ(ui) ∈ uiA ♣♦r t♦s ui ∈ S. ♦s ♣

♣♦♥s ♠♦ s ért♦♥s ♦rt♠qs ♣r♥♣s ♦♥ I. ♦s ♠♦♥

tr♦♥s ♠♠ q DerA(log I) st ΩA(log I).

trtrs P♦ss♦♥ ♦rt♠qs t ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

❯♥ ♦s s ér♥ts ♦r♠s ♦rt♠qs ♦♥strts ♥♦s ♥tr♦s♦♥s

s strtrs P♦ss♦♥ ♦rt♠qs P♦r ♥♦s r♣♣♦♥s q♥ strtr

♦s②♠♣tq sr ♥ rété ♦♠♣① X ♠♥s♦♥ 2n st ♦♥♥é ♥

st♦♥ ω Ω2X(logD) s s r♠s ♦r♠ ér♥t ♦rt♠q

♦♥ ♥ sr rét D X stss♥t s ♣r♦♣rétés s♥ts

ω st r♠é

ωn = ω ∧ ... ∧ ω 6= 0 ♥s H0(X,Ω2n([D])).

♦♥t♦♥ ♠♦♥tr q ♣♦r t♦t r♠ f ♦♥t♦♥ ♦♦♠♦r♣ sr X,

①st ♥ ♥q ♠♣ tr ♦rt♠q δf t q ıδfω = df. ♥ ♦♥sèr

♦rs r♦t f, gω = ω(δf , δg).

s ♣r♦♣rétés t ♦♥ ♠♦♥tr q −,−ω st ♥ strtr P♦s

s♦♥ ♦♦♠♦r♣ ♦rt♠q ♦♥ D. ♦s rst♦♥s ♥♦t♦♥ èr

♥rt t ♥tr♦s♦♥s èr ♥rt ♦rt♠q ♥ r

♥ strtr èr ♥rt ρ : L→ DerA st t ♦rt♠q ♦♥

I s ρ(L) st ♥ s♦s ♠♦ DerA(log I). ♦s ♠♦♥tr♦♥s q t♦t strtr

P♦ss♦♥ ♦rt♠q ♣r♥♣ ♥t sr ΩA(log I) ♥ strtr èr ♥rt ♦rt♠q ♣r s s♦♥ ♣♣t♦♥ ♠t♦♥♥♥ P♦r

♥♦s ♦♥strs♦♥s sr ΩA(log I) ♥ strtr èr ♣r♦♦♥♥t

strtr P♦ss♦♥ ♥t sr ΩA. tt strtr s é♥t sr s é♥értrs

ΩA(log I)− ΩA. Pr

[adu

u, bdv

v] =

a

uu, bdv

v+b

va, vdu

u+ abd(

1

uvu, v).

♥ ♦♥strt ♥s ♥ r♣rés♥tt♦♥ ΩA(log I) ♣r s ért♦♥s ♦rt

♠qs ♦♥ I. ♦♦♠♦♦ tt r♣rés♥tt♦♥ s♣♣ ♦♦♠♦♦

Page 15: Structures de Poisson logarithmiques: invariants

s réstts ♣r♥♣①

P♦ss♦♥ ♦rt♠q ♦s ♠♦♥tr♦♥s q tt ♦♦♠♦♦ st s♦♠♦r♣ à

♦♦♠♦♦ ♠ ♦rt♠q q st s♦♠♦r♣ à ♦♦♠♦♦

P♦ss♦♥ ss♦é ♦rsq strtr P♦ss♦♥ ♦rt♠q ♦♥séré é♦

♥ strtr ♦s②♠♣tq ♠♦②♥ qqs ①♠♣s ♥♦s ♠♦♥tr♦♥s

q♥ é♥ér s ♦♦♠♦♦s P♦ss♦♥ t s P♦ss♦♥ ♦rt♠qs s♦♥t

ér♥ts

Préq♥tt♦♥ ♦rt♠q

♦t ♦r ♥♦s r♠♣ç♦♥s ♥s sé♠ ♣réq♥tt♦♥ r

rété s②♠♣tq ♣r ♥ rété ♦s②♠♣tq (X,D, ω) ♥♦s ♣♦ss à

étr ①t♥s♦♥ s HωX s r♠s ♠♣s trs ♦rt♠qs

♦♠♥t ♠t♦♥♥s rt♠♥t à ω. ♦s r♠♣ç♦♥s ①è♠ ♥

r♠♠ ♣r

0 // CX // (OX , ω) // HωX

// 0

t ♣r♠èr ♣r

0 // OXm // +1 (logD)

σ // DerX(logD) // 0

♦ù +1 (logD) és♥ s r♠s ♦♣értrs ér♥t ♦rt♠qs

♦♥ D. ♥ ♦♥sr♥t ♦r♠ ♥♦s ♥♦s sr♦♥s ♦♦♠♦♦

♠ ♦rt♠q ♣♦r étr ♥térté s ♦r♠s ♦s②♠♣tqs ♦s

♥tr♦s♦♥s ♥♦t♦♥ ért♦♥ ♦♥trr♥t ♦rt♠q à q

♥♦s é♥ss♦♥s ♥♦t♦♥ ss r♥ P♦ss♦♥ ♦rt♠q ♦s ♥♦s ♥

sr♦♥s ♣♦r ♥tr♦r ♥♦t♦♥ ♣réq♥tt♦♥ ♦rt♠q ♦s é♠♦♥

tr♦♥s ♥ té♦rè♠ ♥térté s strtrs P♦ss♦♥ ♦rt♠q ♠♦②♥

♦♦♠♦♦ P♦ss♦♥ ♦rt♠q ss♦é ♥ r s (X,D,Υ) st ♥ r

été P♦ss♦♥ ♦♦♠♦r♣ ♦rt♠q p : L→ X ♥ ré ♥ r♦ts ♦♠♣①s

sr X t Γ(L) s♦♥ ♠♦ st♦♥s ♥ ért♦♥ ♦rt♠q ♦♥trr♥t

Dlog sr p : L → X st ♥ ♣♣t♦♥ C♥ér Ω1X(logD) → EndC(Γ(L)) t

q

Dlogα (fs) = fDlog

α s+ (H(α)f)s

♣♦r t♦t α ∈ Ω1X(logD) t s ∈ Γ(L). ♦s r♠rq♦♥s q s ∇ st ♥ ♦♥♥①♦♥

♦rt♠q sr p : L → X, ♦rs Dα = ∇H(α) st ♥ ért♦♥ ♦♥trr♥t

♦rt♠q sr p : L→ X

s réstts ♣r♥♣①

Prés♥t♦♥s à ♣rés♥t s réstts ss♥ts tt ès

♦t ♦r ♦♥sér♥t sr X = C2 ♦r♠ ω =dy

x♠ér♦♠♦r♣ ♦♥

sr D = 2Y ♦ù Y = (0, y), y ∈ C ♥♦s ♠♦♥tr♦♥s ♥éssté ♠♣♦sr

Page 16: Structures de Poisson logarithmiques: invariants

♣tr ♥tr♦t♦♥ é♥ér

♦♠♠ ②♣♦tès s♣♣é♠♥tr ♦rè♠ ❬t♦ ❪ ♦♥t♦♥ s♦♥

q ♦♥t♦♥ é♥t♦♥ sr ♦t êtr à rré r

♥t s rss ♣rts tr ♥♦s ♦♥s ♦t♥ s réstts s♥ts

♦♥strt♦♥ s èrs P♦ss♦♥ ♦rt♠qs

P♦r t♦t é ♣r♦♣r I ♥ èr ♦♠♠tt ♥tr A ♥♥ré ♣r

S = u1, ..., up ♥♦s ♣♦s♦♥s

DerA(log I) = δ ∈ DerA(log I)δ(ui) ∈ uiA.

st ♠♦ s ért♦♥s ♦rt♠qs ♣r♥♣s ♦♥ I. ♥ ♠♦♥tr

♣tr ♠♠ q

♠♠ DerA(log I) st ΩA(log I).

Pr rs ♥♦s s♦♥s q t♦t strtr P♦ss♦♥ −,− ♦rt♠q sr

A ♦♥ I ♥t ♥ ♣♣t♦♥ H : ΩA → DerA é♥ ♣r H(df) = f,−♣♣é ♣♣t♦♥ ♠t♦♥♥♥ q st ♥ ♦♠♦♠♦r♣s♠ A♠♦s

♣s ♦♥ ♠♦♥tr ♦r ♠♠ q

♠♠ ♣♣t♦♥ ♠t♦♥♥♥ H ss♦é à ♥ strtr P♦ss♦♥

♦rt♠q st à ♠ ♥s DerA(log I).

♥ ♥ ét ss ♠♠ s♥t

♠♠ ♦t S = u1, ...up ♥ st éé♠♥ts A rt♠♥t ♣r

♠èr (ui) 6= (uj) t ui /∈ (uj), uj /∈ (ui) ♣♦r t♦t i 6= j. ♦t −,− ♥

strtr P♦ss♦♥ ♦rt♠q ♣r♥♣ ♦♥ I = 〈S〉A.♦rs

1

uiui,− ∈ DerA(log I) t

1

uiujui, uj ∈ A.

♥ ♥ ét q

♦r♦r −,− st ♥ strtr P♦ss♦♥ ♦rt♠q ♣r♥♣

♦♥ ♥ é I ♥♥ré ♣r ♥ st ♥ éé♠♥ts A rt♠♥t ♣r♠èr

♦rs ♣♣t♦♥ ♠t♦♥♥♥ ss♦é H s ♣r♦♦♥ ♥ ♥ ♦♠♦♠♦r♣s♠

A♠♦s

H : ΩA(log I) → DerA(log I).

♥ ♠♦♥tr ♥ ♣s q H st ♥ ♦♠♦♠♦r♣s♠ èr ♦rsq♦♥ éq♣

ΩA(log I) r♦t é♥ ♠♠

Page 17: Structures de Poisson logarithmiques: invariants

s réstts ♣r♥♣①

♦♥strt♦♥ ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q tqqs ①♠♣s

♦♥strt♦♥ tt ♦♦♠♦♦ r♣♦sé sr té♦rè♠ s♥t

é♦rè♠ ♦t strtr P♦ss♦♥ ♦rt♠q ♣r♥♣ ♦♥ ♥

é I ♥ Rèr A ♥t sr ΩA(log I) ♥ strtr ♥rt

tr♠♥t t ♣♦r t♦t strtr P♦ss♦♥ ♦rt♠q ♣r♥♣ ♦♥ ♥

é I, (ΩA(log I), H, [−,−]) st ♥ èr ♥rt

♦s és♦♥s té♦rè♠ q t♦t strtr P♦ss♦♥ ♦rt♠q ♥t

♥ r♣rés♥tt♦♥ ΩA(log I) ♣r s ért♦♥s ♦rt♠qs ♦s ♣♣♦♥s

♦♥ ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q ♦♦♠♦♦ ss♦é à tt r♣rés♥

tt♦♥ ♦s ♥♦t♦♥s HkPS kè♠r♦♣ ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

ttr P t réér♥ à P♦ss♦♥ ♦rs q ttr S t réér♥ à t♦

♦s és♥♦♥s ♣r HkP kè♠ r♦♣ ♦♦♠♦♦ P♦ss♦♥ ♦s ♠♦♥tr♦♥s

q strtr P♦ss♦♥ é♥ ♣r x, y = x st ♦rt♠q ♣r♥♣

♦♥ é xC[x, y] t ss r♦♣s ♦♦♠♦♦s s♦♥t

Pr♦♣♦st♦♥ s r♦♣s ♦♦♠♦♦ P♦ss♦♥ x, y = x s♦♥t

H0P∼= C H1

P∼= C t H2

P∼= 0A.

♥ ♠♦♥tr ss q ss r♦♣s ♦♦♠♦♦s P♦ss♦♥ ♦rt♠qs s♦♥t

H0PS

∼= C, H1PS

∼= C t H2PS

∼= 0A.

♥ r♠rq q s ① r♦♣s s♦♥t s♦♠♦r♣s st û t q str

tr P♦ss♦♥ x, y = x st ♦s②♠♣tq ♦r♠ ♦s②♠♣tq ss♦é

ω0 =dx

x∧ dy.

Pr rs ♥♦s ♠♦♥tr♦♥s q x, y = x2 é♥t ♥ strtr P♦ss♦♥ ♦

rt♠q ♦♥ x2C[x, y] q ♥st ♣s ♦s②♠♣tq r ♦r♠

ss♦é stdx

x2∧ dy q ♥st ♣s ♦rt♠q ♦♥ x2C[x, y]. Pr ♦♥tr

♥♦s ♠♦♥tr♦♥s q ss r♦♣s ♦♦♠♦♦s P♦ss♦♥ t P♦ss♦♥ ♦rt

♠q s♦♥t s♦♠♦r♣s t ♦♥♥és ♣r

Pr♦♣♦st♦♥ s r♦♣s ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

x, y = x2 s♦♥t

H1PS

∼= C[y]⊕ C1[x];H2PS

∼= C[y], H0PS

∼= C.

s♥st q t êtr ♦s②♠♣tq ♥st ♣s ♥ ♦♥t♦♥ ♥éssr é

té ♥tr s ① r♦♣s ♦♦♠♦♦

♦s ♠♦♥tr♦♥s ss q strtr P♦ss♦♥ (x, y = 0, x, z = 0, y, z =

xyz) ♥s A = C[x, y, z] st ♦rt♠q ♦♥ xyzC[x, y, z] t q s♦♥

tr♦sè♠ r♦♣ ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q st ♥ s♦s r♦♣

s♦♥ tr♦sè♠ r♦♣ ♦♦♠♦♦ P♦ss♦♥

Page 18: Structures de Poisson logarithmiques: invariants

♣tr ♥tr♦t♦♥ é♥ér

é♦rè♠ tr♦sè♠ r♦♣ ♦♦♠♦♦ P♦ss♦♥ ♦rt

♠q strtr P♦ss♦♥ (A = C[x, y, z], x, y = 0, x, z =

0, y, z = xyz) st

H3P∼= C[y]⊕ zC[z]⊕ xC[x]⊕ xyC[y]⊕ xyC[x]⊕xzC[x]⊕ xzC[z]⊕ yzC[y]⊕ yzC[z],

tr♦sè♠ r♦♣ ♦♦♠♦♦ P♦s♦♥ strtr P♦ss♦♥ (A =

C[x, y, z], x, y = 0, x, z = 0, y, z = xyz) st

H3PS

∼= C[y]⊕ zC[z]⊕ xC[x].

♥ s♦♠♠ ♥♦s ♣♦♦♥s ♦♥r q♥ é♥ér s r♦♣s ♦♦♠♦♦

P♦ss♦♥ ♦rt♠q s♦♥t ♥♦♥ tr① t st♥ts ① P♦ss♦♥ ss♦és

r ♥♦♥ trté r ♣r♠t ♥s ♥ rt♥ ♠sr ♦r rô ss

♥t ♥r♥ts

♦s ♠♦♥tr♦♥s q t♦t strtr ♦s②♠♣tq é♥t ♥ t r

été ♥ s s s②♠♣tqs ♠♥s♦♥ ♥

♣♣t♦♥ ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

♣rès ♥ ét ♦♥t♦♥ ♥térté s ♦r♠s ér♥ts ♦rt

♠qs ♥♦s ♥♦s sr♦♥s ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q ♣♦r étr

♣réq♥tt♦♥ s strtrs P♦ss♦♥ ♦s②♠♣tqs ♦s ♣r♦♣♦s♦♥s s

réstts s♥ts

é♦rè♠ ♦t ω ♥ 2♦r♠ ♦rt♠q r♠é ♦♥ ♥ sr

rét D ♥ rété ♦♠♣① X ♠♥s♦♥ 2n. D stst ♣r♦♣rété

é♦rè♠ ♦rs s ♣r♦♣rétés s♥ts s♦♥t éq♥ts

ω =dh

h∧ ψ + η st ♥tér

res(ω) st ①t t ①st [ω0] ∈ H2(X,C) ♥tér t q

[ω0] = [η].

♦s s ②♣♦tèss

D st à r♦s♠♥t ♥♦r♠①

D = ∪j∈IDj st é♦♠♣♦st♦♥ ♥ ♦♠♣♦s♥ts rréts D ♦rs

q Dj st ss I és♥♥t ♥ ♥s♠ ♥s

♦♥sérés ♥s ❬♦t♦ ❪ ♣♦r rtérst♦♥ s sss r♥ ♦rt

♠qs ♥♦s ♠♦♥tr♦♥s q s ∂D és♥ ér♥t P♦ss♦♥ ♦rt♠q

♦rs ♦♥

Pr♦♣♦st♦♥ ♦t (X,D,Υ) ♥ rété P♦ss♦♥ ♦rt♠q ♦♥

♥ sr D stss♥t s ②♣♦tèss t (X,D,Υ) st ♦ ♣réq♥

t s ①st ♥ ♠♣ trs ♦rt♠q δ t ♥ ♦r♠ ♦rt♠q

ω ♥tér t q

Υ+ ∂Dδ = H(ω).

Page 19: Structures de Poisson logarithmiques: invariants

♦tés

♥ r♥♥t à rtérst♦♥ s ♦r♠s ♦rt♠qs ♥térs ♥♦s ♣r♦♦♥s

q

♦r♦r ♦t (X,D,Υ) ♥ rété P♦ss♦♥ ♦rt♠q ♦♥

♥ sr D stss♥t s ②♣♦tèss é♦rè♠ (X,D,Υ) st

♦ ♣réq♥t s ①st ♥ ♠♣ trs ♦rt♠q δ s ♦♥t♦♥s

♦♦♠♦r♣s Ri, i = 1, ..., k t ♥ ♦r♠ ω0 ♦♦♠♦r♣ sr ♥ s♦s rété

♠♥s♦♥ ♥ X ♥tér t q

Υ+ ∂D(δ −k∑

i=1

Ri

hi(H(dhi)) = H(ω0).

♦tés

r s ♦r♠s ér♥ts ♦rt♠qs

♦s ♦♥s s♦♥é à s♦s st♦♥ ♥éssté ♠♣♦sr ♦♥t♦♥

s♦♥ q ♦♥t♦♥ é♥t♦♥ sr ♦t êtr à rré r

♦s ♦♥s ss ♦♥strt ♠♦ s ér♥ts ♦r♠s ♦rt♠qs

♦♥ ♥ é I t ♥♦s ♦♥s rtérsé s♦♥ ♠♦ ♦rsq I st ♥♥ré

♣r ♥ ♥♦♠r ♥ éé♠♥ts èr s♦s♥t

r s strtrs P♦ss♦♥ ♦rt♠qs t ♥r♥ts♦♦♠♦♦qs

tr♠ tt ét ♥♦s s♦♠♠s ♣r♥ à ♠ttr sr ♣ té♦r

P♦ss♦♥ ♦rt♠q ♣s ♥♦s ♦♥s ♠♦♥trr q ♥s s s strtrs

P♦ss♦♥ ♦rt♠qs ♣r♥♣s ♣♣t♦♥ ♠t♦♥♥♥ ss♦é st à ♠

♥s ♠♦ s ért♦♥s ♦rt♠qs t q s ♣r♦♦♥ sr ♠♦

s ér♥ts ♦r♠s ♦rt♠qs ♥s s ♥♦s ♦♥s ♦♥strt sr

♠♦ s ér♥ts ♦r♠s ♦rt♠qs ♥ r♦t ♣r♦♦♥♥t

P♦ss♦♥ ♥t sr ♠♦ s ér♥ts ♦r♠s ♦s ♦♥s

①♣♦té s ♣r♦♣rétés ♣♦r érr ♣♣t♦♥ ♠t♦♥♥♥ ♥t ♣r s str

trs P♦ss♦♥ ♦rt♠qs ♥ strtr èr ♥rt sr ♠♦

s ér♥ts ♦r♠s ♦rt♠qs râ à tt r♥èr ♥♦s ♦♥strs♦♥s

♦♠♣① P♦ss♦♥ ♦rt♠q t ♦♥s qqs r♦♣s ♦♦♠♦♦

s ss♦és ♦s ♦♥s ♠♦♥tré sr s ①♠♣s q s r♦♣s ♦♦♠♦♦

s s♦♥t ♥ é♥érs ér♥ts s r♦♣s ♦♦♠♦♦s P♦ss♦♥ ss♦és

♥ qs ♦ï♥♥t ♦rsq strtr P♦ss♦♥ st ♥t ♣r ♥ strtr

♦s②♠♣tq râ à tt ♥♦ ♦♦♠♦♦ ♥♦s ♦♥s ♥tr♦t ♥♦t♦♥

♣réq♥tt♦♥ ♦rt♠q q ♥♦s ♦♥s é♠♦♥tré ♥ réstt

♣réq♥tt♦♥ ts strtrs ♥♦t♦♥ ért♦♥ ♦♥trr♥t

♦rt♠q

Page 20: Structures de Poisson logarithmiques: invariants

♣tr ♥tr♦t♦♥ é♥ér

Prs♣ts

r s èrs P♦ss♦♥ ♦rt♠qs

♦s ♦♥s ♥tr♦t ♥♦t♦♥ rété P♦ss♦♥ ♦rt♠q t ♦

♦♠♦♦ P♦ss♦♥ ♦rt♠q sr ♥térss♥t étr s ♣r♦♣rétés

érqs s èrs P♦ss♦♥ ♦rt♠q ♥ r♠♣ç♥t sr ♣r ♥

é q♦♥q ♥ èr ss♦t ♦♥♥é ♦s ♦♥s ♦♠♠♥é tt ét

♣tr ♠s ♥♦s ♥♦s s♦♠♠s ♠tés s s strtrs P♦ss♦♥ ♦

rt♠qs ♣r♥♣s sr ♣rtèr♠♥t ♥térss♥t étr s é♥ér

s strtrs P♦ss♦♥ ♦♥t r♦t st ♥ ért♦♥ ♦rt♠q Pr

rs ♦s ♦♥s ♦♥strt ♥s s ♦ù é I st ♥♥ré ♣r ♥ st

♥ éé♠♥ts èr ♠♦ s ér♥ts ♦r♠s ♦

rt♠qs ♥ ♣♦rr rrr s é♥ér ♦ù I st ♥ é q♦♥q ♥

♣♦rr ss rrr ♥♦ ♦rt♠q té♦rè♠ ♦ss♦st♥t

♦s♥r ♥s ❬♦ss t ❪

r s ♦r♠s ér♥ts ♦rt♠qs

qst♦♥ q ♦♥ ♥ ♣t s ♣r♠ttr ♦r st s♦r ♦♠♠♥t

s♦♥t s ♦r♠s ér♥ts ♦rt♠qs ♦♥ s srs ♥♦♥ rét ♥

♣♦rr ♦♥ ♥s ♥ ♣r♦ ♥r s ♣♥r sr st ♣♦r ♦t ♥

♣rt rr s réstts ♥♦s é♦rè♠ ♦♠♣rs♦♥ ♦rt

♠q tr ♣rt rtérst♦♥ s s① s r♠s ♦r♠s ér♥

ts ♦rt♠qs ss♦és t ♥♥ q♥ té♦rè♠ rtérs♥t s srs

♣♦r sqs s s① s♦♥t rs

r q♥tt♦♥

q♥tt♦♥ é♦♠étrq st ssé ♥ ① r♥s ét♣s ♣r♠èr

ét♥t ♣réq♥tt♦♥ ♦s ♥♦s s♦♠♠s ♣s ♦sés sr tt r♥èr ét♣

ét♣ ♣♦rst♦♥ ♠♦②♥ ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q rst

♥①♣♦ré Pr rs srt ♥térss♥t rrr ♠♣t ♦♦♠♦♦

P♦ss♦♥ ♦rt♠q sr q♥tt♦♥ ♣r é♦r♠t♦♥

Page 21: Structures de Poisson logarithmiques: invariants

♣tr

r s strtrs P♦ss♦♥

♦rt♠qs

♦♠♠r èrs P♦ss♦♥ ♦rt♠qs

ért♦♥s ♦rt♠qs

ér♥ts ♦r♠s ♦rt♠qs

éré ♣r r♣♣♦rt à ♥ ért♦♥ ♦rt♠q

trtrs èrs P♦ss♦♥ ♦rt♠qs

qs ①♠♣s èrs P♦ss♦♥ ♦rt♠qs

❱rétés P♦ss♦♥ ♦rt♠qs

sr r

❯♥ r♠rq sr s ♦r♠s ér♥ts ♦rt♠qs t

♠♣s trs ♦rt♠qs

é♥t♦♥ t ♣r♠èrs ♣r♦♣rétés

❱rétés ♦s②♠♣tqs

qs ①♠♣s rétés P♦ss♦♥ ♦rt♠qs

s♣ s SU(2) ♠♦♥♦♣ôs ♠♥étqs r

♥tr♦t♦♥

♣tr st ♦♥sré à ♦♥strt♦♥ èrs P♦ss♦♥ ♦rt♠qs

t rétés P♦ss♦♥ ♦rt♠qs P♦r ♥♦s ♦♥strs♦♥s ♠♦ s

ér♥ts ♦r♠s ♦rt♠qs t ét♦♥s qqs ♥s ss ♣r♦♣rétés

èrs P♦ss♦♥ ♦rt♠qs

♥s tt ♣rt ♦♥ és♥r ♣r

• A ♥ èr ss♦t ♦♠♠tt ♥tr t ♥tèr sr ♥ ♦r♣s k

rtérstq

• I ♥ é A,• U r♦♣ ♠t♣t s ♥tés A.• DerA A♠♦ s ért♦♥s A.• ΩA ♠♦ s ér♥ts är A

Page 22: Structures de Poisson logarithmiques: invariants

♣tr r s strtrs P♦ss♦♥ ♦rt♠qs

ért♦♥s ♦rt♠qs

é♥t♦♥ ♥ ♣♣ ért♦♥ ♦rt♠q ♦♥ ♥ é I A t♦t

éé♠♥t D DerA t q D(I) ⊂ I.

♥ ♥♦tr DerA(log I) ♥s♠ s ért♦♥s A ♦rt♠qs ♦♥ IP♦r t♦s D1, D2 ∈ DerA(log I) ♦♥

D1(D2)(I) ⊂ I.

♥ ♥ ét q DerA(log I) st st ♣♦r r♦t s ért♦♥s

A.

♠♠ DerA(log I) st ♥ s♦s èr DerA.

♦t S = u1, ..., up ♥ s♦s ♥s♠ à p éé♠♥ts A− U .♥ s♣♣♦s ♥s st q I st ♥♥ré ♣r S t ♦♥ és♥r ♣r uA é

A ♥♥ré ♣r u ∈ S.

é♥t♦♥ S st t rt♠♥t ♣r♠r s s é① uiA t ujA s♦♥t ♣r♠rs

t ♥trst♦♥ tr ♣♦r t♦t i, j ts q i 6= j

P♦s♦♥sDerA(log I) := D ∈ DerA(log I);D(ui) ∈ uiA; ♣♦r t♦t ui ∈ S.

P♦r t♦s D ∈ DerA(log I) t ui ∈ S, ♦♥

D(ui)

ui∈ A.

Pr rs ♣♦r t♦s D1, D2 ∈ DerA(log I) ♦♥

D1(D2(ui)) = D1(uib2) ♦ù D2(ui) = uib2= uiD1(b2) + b2D1(ui)

= ui(D1(b2) + b2b1) ♦ù D1(ui) = uib1

P♦r t♦t i = 1, ..., p. ♦♥ DerA(log I) st st ♣♦r r♦t s ér

t♦♥s A. ♦ù ♠♠ s♥t

♠♠ DerA(log I) st ♥ s♦s èr DerA(log I).

é♥t♦♥ s éé♠♥ts DerA(log I) s♦♥t ♣♣és ért♦♥s ♦rt♠qs

♣r♥♣s ♦♥ I.

ér♥ts ♦r♠s ♦rt♠qs

P♦s♦♥s MA té♦r s A♠♦s

Pr♦♣♦st♦♥ ♥♦♦♥tr Der(A,−) MA st r♣rés♥t

Page 23: Structures de Poisson logarithmiques: invariants

èrs P♦ss♦♥ ♦rt♠qs

Pr ♣rès ♣r♦♣rété ♥rs ♣r♦t t♥s♦r A⊗A ♣♣t♦♥

m : A⊗A → A(a, b) 7→ ab

♥t ♣r ♣r♦t A, st ♥ ♦♠♦♠♦r♣s♠ kèrs ♥ ♣♦s ker(m) =

I t ♦♥ ♠♦♥tr q I st ♥As♦s ♠♦ A⊗A ♥♥ré ♣r a⊗1A−1A⊗a, a ∈A. s ♠♦s q♦t♥ts B = A⊗A/I2 t ΩA = I/I2 s♦♥t ♦♥ ♥ é♥s

tr ♣rt a = m(1⊗a) ♣♦r t♦t a ∈ A. ♦♥ m ♥t ♥ s♦♠♦r♣s♠

A ⊗A/I ≃ A q à s♦♥ t♦r ♥t ♥ é♣♠♦r♣s♠ m : B → A → 0. ♥ ♦♥

st ①t ♦rt s♥t

0 → ΩA → B → A→ 0.

Pr rs s ♠♦r♣s♠s

λ1 : A → B, a 7→ a⊗ 1 + I2λ2 : A → B, a 7→ 1⊗ a+ I2

ér♥t s étés s♥ts mλ1 = mλ2 = 1A. s♦♥t ♦♥ s st♦♥s tt

①t♥s♦♥ ♣s s étés mλ1 = mλ2 = 1AA s♥st q λ1 t λ2 s♦♥t s

rè♠♥ts 1A ♦♥ λ1 − λ2 = d st ♥ éé♠♥t Der(A,ΩA)

P♦r r ♣r ♥♦s ♦♥s ♠♦♥trr q (ΩA, d) st ♥rs

♦t D ∈ Der(A,M) ♣♣t♦♥ ϕ : A⊗A →M ⊕A

x⊗ y 7→ (xy, xDy) = (m(x⊗ y), xDy)

st ♥ ♦♠♦♠♦r♣s♠ kèrs q st A♥ér

Psq m(∑xi ⊗ yi) =

∑xiyi = 0 ♣♦r t♦t

∑xi ⊗ yi ∈ I, ♦rs rstrt♦♥

ϕ : ϕ |I : I −→ M st A♥ér ♣s t q ϕ(I2) = 0 ♠♣q I2 ⊂ ker ϕ.

s♥st q ϕ ♥t ♥ ♦♠♦♠♦r♣s♠ f : ΩA −→ M t q f π = ϕ ♦ù π

és♥ ♣r♦t♦♥ ♥♦♥q I sr I/I2. Pr rs ♣♦r t♦t a ∈ A, ♦♥

f(da) = f(1⊗ a− a⊗ 1 + I2)

= ϕ(1⊗ a− a⊗ 1)

= Da

è é♠♦♥strt♦♥

é♥t♦♥ ΩA st ♣♣é ♠♦ s ér♥ts ♦r♠s

Pr♦♣♦st♦♥ ♠♦♥tr q ♣♦r t♦t A♠♦ M, ①st ♥ s♦♠♦r

♣s♠ σM : Hom(ΩA,M) ∼= Der(A,M). ♥s st s♦♠♦r♣s♠ σA :

Hom(ΩA,A) ∼= Der(A) sr ♥♦té σ.

ér♥ts ♦rt♠qs

é♥t♦♥ ♥ ♣♣ ♠♦ s ♦r♠s ér♥ts ♦rt♠qs ♦♥

I A♠♦ DerA(log I).

Page 24: Structures de Poisson logarithmiques: invariants

♣tr r s strtrs P♦ss♦♥ ♦rt♠qs

♥ ♣♦s

ΩA(log I)

A♠♦ ♥♥ré ♣r

duiui, ui ∈ S, i = 1, ..., p

∪ ΩA.

é♥t♦♥ ΩA(log I) st ♣♣é ♠♦ s ér♥ts ♦r♠s A ♦

rt♠qs ♦♥ I.

♦t δ ∈ DerA(log I). ♣rès ♣r♦♣♦st♦♥ δ ♥t ♥ ♣♣t♦♥ A

♥ér

σ(δ) : ΩA → A

t q

σ(δ) d = δ.

♦♥ ♣♦r t♦t u ∈ S, ①st ϕ(u) ∈ A t q

σ(δ)(du) = δu = uϕ(u)

t ♦♥1

uσ(δ)(du) = ϕ(u) ∈ A.

♥ ♣♣t♦♥ ♥ér s♥t

σ(δ) : ΩA(log I) −→ Aadu

u+ bdf 7→ a

1

uσ(δ)(du) + bσ(δ)(df).

ér σ(δ1 + gδ2)(adu

u+ bdf) = σ(δ1)(a

du

u+ bdf) + gσ(δ2)(

du

u+ bdf).

♥t ♦♥ ♥ ♣♣t♦♥ A♥ér

σ : DerA(log I) −→ HomA(ΩA(log I),A)

δ 7→ σ(δ) : adu

u+ bdf 7→ a

1

uσ(δ)(du) + bσ(δ)(df)

q st ♥ s♦♠♦r♣s♠

♥ t ♣♦r t♦t f ∈ HomA(ΩA(log I),A) ♦♥ f d ∈ DerA(log I).♥ ♦♥sèr ♦♠♦♠♦r♣s♠ A♠♦s

ψ : HomA(ΩA(log I),A) → DerA(log I)f 7→ f d.

P♦r t♦t δ ∈ DerA(log I) ♦♥

ψ σ(δ) = ψ(σ(δ))

= σ(δ) d= δ.

Page 25: Structures de Poisson logarithmiques: invariants

èrs P♦ss♦♥ ♦rt♠qs

♦♥ ψ σ = id DerA(log I).

♠ê♠ ♣♦r t♦s f ∈ HomA(ΩA(log I),A) t u ∈ S ♦♥

[(σ ψ)(f)](du) = [σ(ψ(f))](du)

= [σ(f d)](du)= σ(f d)(du)= (f d)u= f(du)

Pr rs[(σ ψ)(f)](duu ) = σ(f d)(duu )

=1

u(σ(f d)(du))

=1

uσ(f d) d(u)

=1

u(f d)(u)

= f(duu ).

♣♦r t♦t u ∈ S.♦♥

(σ ψ)(f) = f ♣♦r t♦t f ∈ HomA(ΩA(log I),A). t ♦♥ σ ψ =

idHomA(ΩA(log I),A). ♣r♦ ♠♠ s♥t

♠♠ DerA(log I) st ΩA(log I).P♦r t♦s fda ∈ ΩA t δ ∈ DerA ♦♥

σ(δ)(fda) = f(σ(δ) d)(a)= fδ(a).

♥ ♦♥sèr ♣♣t♦♥

θ : ΩA → Hom(DerA,A)

ω 7→ θ(ω) : δ 7→ σ(δ)(ω)

θ st ♣r ♦♥strt♦♥ ♥ ♦♠♦♠♦r♣s♠ A♠♦s

Pr rs ♣♦r t♦s δ ∈ DerA(log I) t u ∈ Sθ(du)δ = σ(δ)(du)

= (σ(δ) d)u= δ(u) ∈ uA.

♦♥1

uθ(du)(δ) ∈ A ♣♦r t♦t δ ∈ DerA(log I) t u ∈ S.

θ ♥t ♦♥ ♥ ♦♠♦♠♦r♣s♠ A♠♦s

Θ : ΩA(log I) −→ Hom( DerA(log I),A)

fdu

u+ gda 7→ f

uθ(du) + gθ(da)

q s ♣r♦♦♥ ♥ ♦♠♦♠♦r♣s♠ èrs rés

Θ :∧ΩA(log I) −→ Lalt( DerA(log I),A)

Page 26: Structures de Poisson logarithmiques: invariants

♣tr r s strtrs P♦ss♦♥ ♦rt♠qs

éré ♣r r♣♣♦rt à ♥ ért♦♥ ♦rt♠q

♥ ♥♦t∧

A[ΩA(log I)] :=⊕n∈N

∧nA[ΩA(log I)] Aèr ①térr A

♠♦ ΩA(log I). ért♦♥

d : A → ΩA

♦♥ ét ért♦♥

d : A → ΩA(log I) a 7→

da s a ∈ A− I∗

ada

as a ∈ I∗

d s ♣r♦♦♥ ♥ ♥ ért♦♥ éré

d :∧

A

[ΩA(log I)] →∧

A

[ΩA(log I)]

t q ♦♣ (∧

A[ΩA(log I)], d) s♦t ♥ ♦♠♣① ér♥t

P♦r t♦t δ ∈ DerA(log I) t t♦t ♥tr p ≥ 1 ♣♣t♦♥

σδ : [ΩA(log I)]p →∧

A

[ΩA(log I)], (ω1, ..., ωp) 7→p∑

i=1

(−1)i−1σ(δ)(ωi)ω1∧ω2∧...∧ωi∧...ωp

st A♠t♥ér tr♥é ♥ ♥♦t

iδ :∧

A

[ΩA(log I)] →∧

A

[ΩA(log I)]

♥q ♣♣t♦♥ A♥ér t q

iδ(ω1 ∧ ω2 ∧ ... ∧ ωp) 7→p∑

i=1

(−1)i−1σ(δ)(ωi)ω1 ∧ ω2 ∧ ... ∧ ωi ∧ ...ωp

♣♦r t♦t p

♠♠ ♣♣t♦♥ iδ st ♥ ért♦♥ ré −1

Pr ♣r st s♠♣ t rt

é♥t♦♥ ♦♣értr ré ③ér♦ Lδ := iδ d + d iδ st ♣♣é éré

♣r r♣♣♦rt à ért♦♥ ♦rt♠q δ.

♣r♦♣♦st♦♥ s♥t ♦♥♥ qqs ♣r♦♣rétés Lδ

Pr♦♣♦st♦♥ P♦r t♦t δ ∈ DerA(log I), ω ∈ ΩA(log I) t a ∈ A, ♦♥

Laδ(ω) = aLδ(ω) + (σ(δ))(ω)d(a)

Lδ(aω) = δ(a).ω + aLδω Lδ(d(a)) = d[δ(a)]

Page 27: Structures de Poisson logarithmiques: invariants

èrs P♦ss♦♥ ♦rt♠qs

Pr

P♦r t♦t a ∈ A t ω ∈ ΩA(log I), ♦♥

Laδ(ω)= iaδ(d(ω)) + d(iaδ(ω))

= aiδ(d(ω)) + d(aiδ(ω))

= aiδ(d(ω)) + iδ(ω)d(a) + ad(iδ(ω))

= aLδω + σ(δ)(ω)d(a)

P♦r t♦s a ∈ A t ω ∈ ΩA(log I), ♦♥

Lδ(aω)= iδ(d(aω)) + d(iδ(aω))

= iδ(ad(ω) + da ∧ ω) + d(aiδ(ω))

= aiδ(d(ω)) + iδ(d(a) ∧ ω) + ad(iδω) + iδ(ω)d(a)

= aiδ(d(ω)) + σ(δ)(d(a))ω − σ(δ)(ω)d(a) + ad(iδ(ω)) + σ(δ)(ω)d(a)

= aLδω + σ(δ)d(a)ω

P♦r t♦t a ∈ A, ♦♥

Lδ(d(a)= iδ(d(d(a))) + d(iδ(d(a)))

= d(iδ(d(a)))

= d(σ(δ) d(a))

trtrs èrs P♦ss♦♥ ♦rt♠qs

trtrs èrs P♦ss♦♥

❯♥ èr P♦ss♦♥ st ♥ èr ss♦t A ♠♥ ♥ ♣♣t♦♥

♥ér −,− ♥ts②♠étrq ér♥t s ① ♣r♦♣rétés s♥ts

a, b, c+ b, c, a+ c, a, b = 0 ♥tté ♦

a, bc = ba, c+ ca, b ♣r♦♣rété ♥③

♥ ♥ ét ♦♥ q ♣♦r t♦t a ∈ A ♣♣t♦♥

ada : A → A, b 7→ a, b

st ♥ ért♦♥ sr A. ♣s ♣♦r t♦s a, b ∈ A, ♦♥

adab(x) = ab, x = ab, x+ ba, x

s♥st q ♣♣t♦♥ ad : A → DerA, a 7→ ada st ♥ ért♦♥ sr

A à rs ♥s A♠♦ DerA. ♥t ♣rès ♣r♦♣♦st♦♥ ♥

♦♠♦♠♦r♣s♠ A♠♦s

H : ΩA → DerA

Page 28: Structures de Poisson logarithmiques: invariants

♣tr r s strtrs P♦ss♦♥ ♦rt♠qs

t q H d = ad.

H st ♣♣é ♣♣t♦♥ ♠t♦♥♥♥ ss♦é à −,−.♥ ♥ ét ♥ ♦♠♦♠♦r♣s♠ A♠♦s

−σ H : ΩA → Hom(ΩA,A)

à ♣rtr q ♦♥ é♥t ♣♣t♦♥

ω : ΩA × ΩA → A, (x, y) 7→ −[(σ H)(x)]y

ω st ♥ ♦r♠ A♥ér tr♥é

♥ t ♣♦r t♦t x =∑

j∈J ;J♥

ajdbj ∈ A, ♦♥

ω(x, x) = −[σ H)(x)](x)

= −∑

j∈J ;J♥

aj [σ(H(x))]dbj

= −∑

j∈J ;J♥

aj [H(x)]bj

= −∑

j∈J ;J♥

aj∑

k∈J ;J♥

ak[H(dbk)]bj

= −∑

j∈J ;J♥

aj∑

k∈J ;J♥

ak[ad(bk)]bj

= − ∑j,k∈J ;J♥

ajakbk, bj

= 0

ω st ♣♣é ♦r♠ P♦ss♦♥ ss♦é à −,−.♦rsq A és♥ èr C∞(M) s ♦♥t♦♥s ér♥ts sr ♥ rété

P♦ss♦♥ M, ω st ♣♣é t♥sr P♦ss♦♥ ♦ tr P♦ss♦♥

Pr rs ♣♦r t♦t a, b ∈ A ♦♥

ω(da, db) = −[σ(H(da))](db)

= −[σ(H(da))] d(b)= −H(da)b

= −a, b

t ♣r stLH(da)db = d(iH(da)db)

= d(H(da)b)

= d(H(da)b)

= da, b

Pr♦♣♦st♦♥ P♦r t♦t èr P♦ss♦♥ A ♦r♠ P♦ss♦♥ ω, ♣

♣t♦♥

[−,−] : ΩA × ΩA −→ ΩA

(x, y) 7→ d(ω(x, y)) + LH(x)y − LH(y)x

é♥t ♥ strtr kèr sr ΩA. ♣s

Page 29: Structures de Poisson logarithmiques: invariants

èrs P♦ss♦♥ ♦rt♠qs

[x, ay] = (H(x))(a)y + a[x, y]

s ♣♣t♦♥s

d : A → ΩA

t

H : ΩA → DerA

s♦♥t s ♦♠♦♠♦r♣s♠s kèrs

s♥st q t♦t strtr P♦ss♦♥ −,− ♥t sr ΩA ♥ strtr

èr ♥rt ♥ ♣rtr ♣♦r x = adu, y = bdv ∈ ΩA ♦♥

♥ ♣rt

d(ω(adu, bdv)) = −d(abu, v) = −au, vdb− bu, vda− abdu, v,

tr ♣rt

LH(adu)bdv = au, bdv + abd(u, v) + bu, vdaLH(bdv)adu = bv, adu+ abd(v, u) + av, udb.

♦♥

[adu, bdv] = −au, vdb− bu, vda− abdu, v+ au, bdv+abd(u, v) + bu, vda− bv, adu− abd(v, u)− av, udb.

t ♣r st

[adu, bdv] = au, bdv + ba, vdu+ abdu, v.

trtr P♦ss♦♥ ♦rt♠q

♣rès q ♣réè t♦t strtr P♦ss♦♥ ♥s A st ♥ ért♦♥

sr A t DerA(log I) st ♥ s♦s èr DerA.

é♥t♦♥ ❯♥ strtr P♦ss♦♥ −,− sr A st t ♦rt♠q ♦♥

I s st ♥ ért♦♥ ♦rt♠q ♦♥ I

♦t −,− ♥ strtr P♦ss♦♥ ♦rt♠q ♦♥ I. P♦r t♦s a ∈ At u ∈ I ♦♥

a, u ∈ A, I ⊂ I♦♥ a,− st ♥ ért♦♥ ♦rt♠q ♦♥ I s♥st ♦♥ q ♣♦r

t♦t a ∈ A,H(da) = a,− ∈ DerA(log I).

♠♠ ♣♣t♦♥ ♠t♦♥♥♥ H t♦t strtr P♦ss♦♥ ♦

rt♠q st à rs ♥s DerA(log I).

é♥t♦♥ ❯♥ strtr P♦ss♦♥ −,− sr A st t ♦rt♠q ♣r♥

♣ ♦♥ I s ♣♦r t♦t u ∈ Su,− ∈ DerA(log I).

Page 30: Structures de Poisson logarithmiques: invariants

♣tr r s strtrs P♦ss♦♥ ♦rt♠qs

♦s r♠rq♦♥s q s −,− st ♥ strtr P♦ss♦♥ ♦rt♠q ♣r♥♣

♦♥ I, ♦rs ♣♦r t♦t x ∈ S ①st ♥ ♣♣t♦♥ ϕx : A → A t q

x, a = xϕx(a)

♣♦r t♦t a ∈ A. ♥s s −,− st ♥ strtr P♦ss♦♥ ♦rt♠q ♣r♥

♣ ♦♥ I ♦rs ♣♦r t♦s x ∈ S t a, b ∈ A, ♦♥

x, ab = ax, b+ bx, a= x(aϕx(b) + bϕx(a))

t

x, ab = xϕx(ab)

♦♥

ϕx(ab) = aϕx(b) + bϕx(a).

Pr rs ♣♦r t♦s x, y ∈ S ♦♥

xϕx(y) = x, y = −yϕy(x). ♣s I st ♣r♠r ♦rs ①st bxy ∈ I t q

x, y = xybxy.

♥ ♥ ét q

ϕx(ay) ∈ yA.P♦r t♦s a ∈ A t y ∈ S. ♣s I st ♣r♠r ♦rs ϕx ∈ DerA(log I) ♣♦r

t♦t x ∈ S.♥ ♥ ét ♠♠ s♥t

♠♠ ♦t S = u1, ...up ♥ s♦s ♥s♠ A rt♠♥t ♣r♠r

(ui) 6= (uj) t ui /∈ (uj), uj /∈ (ui) ♣♦r t♦t i 6= j. ♦t −,− ♥ strtr

P♦ss♦♥ ♦rt♠q ♣r♥♣ ♦♥ I = 〈S〉A.♦rs

1

uiui,− ∈ DerA(log I) t

1

uiujui, uj ∈ A

♥ s♣♣♦s q♥ ♣s s éé♠♥ts S s♦♥t rt♠♥t ♣r♠rs q ♠♣q

q ♣♦r t♦t u ∈ S, 1

uH(du) ∈ DerA(log I). ♥ ♥ ét ♦♠♦♠♦r♣s♠

A♠♦s

H : ΩA(log I) → DerA(log I)é♥ ♣r

ΩA(log I) ∋ x =∑

ui∈S,ai∈A

aiduiui

+∑

vj∈A,i∈J,bj∈A,J♥

bjdvj

_

H∑

ui∈S,ai∈A

aiuiH(dui) +

∑vj∈A,i∈J,bj∈A,J♥

bjH(dvj)

.

♥ H|ΩA= H.

Page 31: Structures de Poisson logarithmiques: invariants

èrs P♦ss♦♥ ♦rt♠qs

♦r♦r −,− st ♥ strtr P♦ss♦♥ ♦rt♠q ♣r♥

♣ ♦♥ ♥ é I ♥♥ré ♣r ♥ st ♥ éé♠♥ts A rt♠♥t

♣r♠èr ♦rs ♣♣t♦♥ ♠t♦♥♥♥ ss♦é H s ♣r♦♦♥ ♥ ♥ ♦♠♦♠♦r

♣s♠ A♠♦s

H : ΩA(log I) → DerA(log I).

é♥t♦♥ H st ♣♣é ♣♣t♦♥ ♠t♦♥♥♥ ♦rt♠q ss♦é à

strtr P♦ss♦♥ ♦rt♠q ♣r♥♣ −,−.

♦r♦r t ♣r ♠♠ ♦♥ ét q t♦t strtr

P♦ss♦♥ ♦rt♠q ♣r♥♣ ♥t ♥ ♦♠♦♠♦r♣s♠ A♠♦s

Φ : ΩA(log I) → Hom(ΩA(log I),A)

α 7→ σ H(α)

♥ ♥ ét ♦♥ ♦r♠ s♥t sr ΩA(log I)

π(α, β) := [Φ(x)]y.

Pr♦♣♦st♦♥ π st ♥ ♦r♠ tr♥é sr ΩA(log I).

Pr ♦t x =p∑i=1xiduiui

+n∑

i=p+1xidai ∈ ΩA(log I).

[Φ(x)](x) = [p∑1

xiui[σ H d](ui) +

n∑p+1

xi[σ H d](ai)](x)

=p∑1

xiui[σ H d](ui)[

p∑j=1

xjdujuj

+n∑

j=p+1xjdaj ]+

+n∑p+1

xi[σ H d](ai)[p∑j=1

xjdujuj

+n∑

i,j=p+1xid(aj)]

=p∑

i,j=1

xixjuiuj

σ[H d(ui)] d(uj)+

+n∑

i,j=p+1

xixjui

σ[H d(ui)] d(aj)+

+n∑

i,j=p+1

xixjuj

σ[H d(ai)] d(uj)+

+n∑

i,j=p+1xixj σ[H d(ai)] d(aj)

=p∑

i,j=1

xixjuiuj

ui;uj+n∑

1≤i≤p,p+1≤j≤n

xixjui

ui; aj

+n∑

1≤j≤p,p+1≤i≤n

xixjuj

ai;uj+n∑

i,j=p+1xixjai; aj = 0

t♥t ♦♥♥é q ΩA st ♥ s♦s ♠♦ ΩA(log I), ♠♦ s ♦r♠s

Page 32: Structures de Poisson logarithmiques: invariants

♣tr r s strtrs P♦ss♦♥ ♦rt♠qs

tr♥és sr ΩA(log I) st ♦♥t♥ ♥s ♠♦ s ♦r♠s tr♥és sr ΩA.

π ♣t ♦♥ ♦♣érr sr du⊗ dv ♣♦r t♦t u, v ∈ A.♥ ♦♥ π(du, dv) = [Φ(du)]dv = σ(H(du))dv = H(du)v = u, v. ♠♠ ss♦s ♦♥♥ qqs ♣r♦♣rétés π

♠♠ ♦t π ♦r♠ ss♦é à ♥ strtr P♦ss♦♥ ♦rt♠q

♣r♥♣ −,−. P♦r t♦t u, v ∈ S, a, b ∈ A ♦♥

π(adu

u, bdv

v) =

ab

uvu, v

π(adu, bdv

v) =

ab

vu, v

π(adu, bdv) = abu, v

Pr P♦r q st ♣r♠èr ♣r♦♣rété ♦♥sér♦♥s

u, v ∈ S t a, b ∈ A. ♣rès é♥t♦♥ π, ♦♥

π

(adu

u, bdv

v

)= Φ(a

du

u)bdv

v

=ab

uvσ(u,−)dv

=ab

uvu, v

Pr ♥ rs♦♥♥♠♥t ♥♦ ♦♥ é♠♦♥tr s ♣r♦♣rétés rst♥ts

qs ①♠♣s èrs P♦ss♦♥ ♦rt♠qs

♠♠ ♦t (A, −,−0) ♥ èr P♦ss♦♥ P♦r t♦t a0 ∈ A, a0 6=0A,

−,− := a0−,−0 st ♥ strtr P♦ss♦♥ ♥s A s t s♠♥t s ♣♦r

t♦t a, b, c ∈ A,

a, a00b, c0 + b, a00c, a0 + c, a00a, b0 = 0A

Pr t ♠♦♥trr q −,− = a0−,− ér ♥tté ♦ s t

s♠♥t s été st stst Pr rs −,− ér ♥tté

♦ s t s♠♥t s a, b, c+ b, c, a+ c, a, b = 0A. q éqt

à 0 = a, b, c+ b, c, a+ c, a, b

= a0a, a0b, c00 + a0b, a0c, a00 + a0c, a0a, b00= a0(a, a00b, c0 + b, a00c, a0 + c, a00a, b0)+

+a20(a, b, c00 + b, c, a00 + c, a, b00)= a0(a, a00b, c0 + b, a00c, a0 + c, a00a, b0)

réstt s ét ♥térté A.♥ ♣rtr été st t♦♦rs éré ♣♦r t♦t s♠r a0 ∈ A

−,−0.

Page 33: Structures de Poisson logarithmiques: invariants

èrs P♦ss♦♥ ♦rt♠qs

♦r♦r ♦t −,−0 ♥ strtr P♦ss♦♥ ♥s A.a0−,−0 st ♥ strtr P♦ss♦♥ ♦rt♠q ♦♥ é a0A ♣♦r

t♦t a0 ∈ A ér♥t

♥ é♠♥t ♦r♦r s♥t

♦r♦r ♦t A := k[x, y] ♦ A = k[x, y, z] t a0 ∈ A. P♦r t♦t str

tr P♦ss♦♥ −,−0 ♥s A, a0−,−0 st ♥ strtr P♦ss♦♥ ♥s A♦rt♠q ♣r♥♣ ♦♥ a0A.

Pr ❱♦r ♥♥①

①♠♣ r A := C[x, y, t, z] ♦♥ é♥t r♦t

f, g = xyz

(∂f

∂x

∂g

∂y− ∂f

∂y

∂g

∂x

)+∂f

∂t

∂g

∂z− ∂f

∂z

∂g

∂t

♦♥tr♦♥s q −,− é♥ ♣r st ♥ r♦t P♦ss♦♥ ♥s A.• rè ♥③ t ♥ts②♠étrq é♦♥t été s♥t

xyz

(∂f

∂x

∂g

∂y− ∂f

∂y

∂g

∂x

)+∂f

∂t

∂g

∂z−∂f∂z

∂g

∂t= xyz

df ∧ dg ∧ dt ∧ dzdx ∧ dy ∧ dt ∧ dz+

df ∧ dg ∧ dx ∧ dydx ∧ dy ∧ dt ∧ dz

• P♦r q st ♥tté ♦ st ♠♦♥trr ♣rès

❬♥r♦③ ❪ q

[π, π] = 0

♦ù [−,−] és♥ r♦t ♦t♥ t π = xyz∂

∂x∧ ∂

∂y+∂

∂t∧ ∂

∂zés♥

tr ss♦é à −,−.P♦r st érr q

[xyz∂

∂x∧ ∂

∂y, xyz

∂x∧ ∂

∂y] = 0, [

∂t∧ ∂

∂z,∂

∂t∧ ∂

∂z] = 0

t [xyz∂

∂x∧ ∂

∂y,∂

∂t∧ ∂

∂z] = 0.

Pr rs ért♦♥ Df := f,− = xyz(∂f

∂x

∂y− ∂f

∂y

∂x) +

∂f

∂t

∂z− ∂f

∂z

∂tér Dz(xyz) = xy /∈ (xyz)A. ♥st ♦♥ ♣s ♥ strtr P♦ss♦♥ ♦

rt♠q ♦♥ (xyz)A. ♣♥♥t st ♦rt♠q ♣r♥♣ ♦♥

(xy)A.

①♠♣ r A := C[x, y, z], ♦♥ s ♦♥♥ ① éé♠♥ts h, p ∈ A ♥♦♥

♦♥st♥ts r♦t

f, ghp := hdf ∧ dg ∧ dpdx ∧ dy ∧ dz +

df ∧ dg ∧ dhdx ∧ dy ∧ dz .

st ♥ér ♥ts②♠étrq t stst rè ♥③

P♦r ♠♦♥trr q r♦t st P♦ss♦♥ st ♦♥ érr ♥tté

Page 34: Structures de Poisson logarithmiques: invariants

♣tr r s strtrs P♦ss♦♥ ♦rt♠qs

♦ ♥♥t ♦♠♣t s ♣r♦♣rétés ért♦♥s r♥r st

♠♦♥trr q

z, x, yhphp + x, y, zhphp + y, z, xhphp = 0

P♦r ♦♥ r♠rqr q

x, yhp = h∂p

∂z+∂h

∂z

♥ ♣♦s♥t H = x, yhp, ♥ ♣♣t♦♥ s♠♣ s é♥t♦♥s ♦♥♥

z, x, yhphp = h

(∂H

∂x

∂p

∂y− ∂H

∂y

∂p

∂x

)+

(∂H

∂x

∂h

∂y− ∂H

∂y

∂h

∂x

)

♥ sstt ♥s tt été∂H

∂yt∂H

∂x♣r

∂H

∂x=∂h

∂x

∂p

∂z+ h

∂2p

∂xz+∂2h

∂xz.

∂H

∂y=∂h

∂y

∂p

∂z+ h

∂2p

∂yz+∂2h

∂yz.

t ♦♥ ♦t♥t

z, x, yhphp + x, y, zhphp + y, z, xhphp =

= h2∂p

∂y

∂2p

∂xz+ h

∂p

∂y

∂2h

∂xz− h2

∂p

∂x

∂2p

∂yz− h

∂p

∂x

∂2h

∂yz+∂h

∂y

∂2h

∂xz− h

∂h

∂x

∂p

∂yz− ∂h

∂x

∂h

∂yz+

h2∂p

∂z

∂2p

∂yx+ h

∂p

∂z

∂2h

∂yx− h2

∂p

∂y

∂2p

∂zx− h

∂p

∂y

∂2h

∂zx+∂h

∂z

∂2h

∂yx− h

∂h

∂y

∂p

∂zx− ∂h

∂y

∂h

∂zx+

h2∂p

∂x

∂2p

∂zy+ h

∂p

∂x

∂2h

∂zy− h2

∂p

∂z

∂2p

∂xy− h

∂p

∂z

∂2h

∂xy+∂h

∂x

∂2h

∂zy− h

∂h

∂z

∂p

∂xy− ∂h

∂z

∂2h

∂xy= 0.

♦♥ −,−hp st ♥ ♥ strtr P♦ss♦♥ sr A. ♣s ♣♦r t♦t f ∈ A,♦♥

f, hhp = hdf ∧ dh ∧ dpdx ∧ dy ∧ dz ∈ hA.

♥ ♦♥t ♦♥ q −,−hp st ♦rt♠q ♦♥ hA.

①♠♣ ♦♥t (Qi)1≤i≤n−2 (n − 2) éé♠♥ts C[x1, ..., xn]. P♦r t♦t

λ ∈ C[x1, ..., xn], r♦t

f, g = λdf ∧ dg ∧ dQ1 ∧ ... ∧ dQn−2

dx1 ∧ .... ∧ dxnst ♥ strtr P♦ss♦♥ ♥s

C[x1, ..., xn] ♦rt♠q ♦♥ λC[x1, ..., xn].

Pr♦♣♦st♦♥ ♦t strtr P♦ss♦♥ ♥s C[x, y] st s♦t s②♠♣tq

s♦t ♦rt♠q

Pr ♦t −,− ♥ strtr P♦ss♦♥ ♥s C[x, y].

P♦r t♦t f, g ∈ C[x, y], ♦♥

f, g = x, y(∂f∂x

∂g

∂y− ∂f

∂y

∂g

∂x)

Prt♥t −,− st s②♠♣tq s x, y ∈ C∗. ♥s s ♦♥trr st

♦rt♠q ♦♥ x, yC[x, y].

Page 35: Structures de Poisson logarithmiques: invariants

❱rétés P♦ss♦♥ ♦rt♠qs

❱rétés P♦ss♦♥ ♦rt♠qs

tt ♣rt st ♦♥sré à ♦♥strt♦♥ é♦♠étrq ♥♦t♦♥ strtr

P♦ss♦♥ ♦rt♠q

♥s tt ♣rt s ♠♥t♦♥ ①♣t♦♥♥ ♦♥ és♥r ♣r

• X ♥ rété ♦♠♣① ♠♥s♦♥ ♦♠♣① n,

• OX s s r♠s ♦♥t♦♥ ♦♦♠♦r♣s

• ΩX s s r♠s s ♦r♠s ♦♦♠♦r♣s sr X,

• MD s s r♠s s ♦r♠s ♠ér♦♠♦r♣s sr D.

sr r

♦t U ♥ ♦♠♥ Cn t D ⊂ U ♥ ②♣rsr U é♥ ♣r éq

t♦♥ h(z) = 0, ♦ù h st ♥ ♦♥t♦♥ ♦♦♠♦r♣ ♦rs ♣♦r t♦t q♦r♠ ω

♠ér♦♠♦r♣ ♥s U à ♣ôs ♥s D, ♦♥ té♦rè♠ s♥t

é♦rè♠ ❬t♦ ❪ s ♣r♦♣rétés s♥ts s♦♥t éq♥ts

hω t hdω s♦♥t ♦♦♠♦r♣s

hω t dh ∧ ω s♦♥t ♦♦♠♦r♣s

①st ♥ ♦♥t♦♥ ♦♦♠♦r♣ g t ♥ (q − 1)♦r♠ ξ t ♥ q♦r♠

♦♦♠♦r♣ η sr U t q

dimCD ∩ z ∈ U : g(z) = 0 ≤ n− 2

gω =dh

h∧ ξ + η

①st ♥ s♦s s♣ ♥②tq ♠♥s♦♥ (n − 2) A ⊂ D t q s

r♠s ω ♥ t♦t ♣♦♥t p ∈ D−A s♦♥t ♦♥t♥s ♥sdh

h∧Ωq−1

U,p +ΩqU,p.

té♦rè♠ st é♥t♦♥ s♥t

é♥t♦♥ ❯♥ q♦r♠ ♠ér♦♠♦r♣ sr U st ♦rt♠q ♦♥ D s

stst s ♦♥t♦♥s éq♥ts é♦rè♠

P♦r t♦t ♣♦♥t p X t t♦t ♥tr ♥tr q, ♦♥ ♥♦t

ΩqX,p(logD) := r♠ s q♦r♠s ♦rt♠qs ♥ ♣

ΩqX(logD) := ∪p∈X

ΩqX,p(logD)

Pr rs ♣r♦♣♦st♦♥ s♥t ♥♦s ♣r♠t é♥r ♥♦ é♦♠étrq

♥♦t♦♥ ért♦♥ ♦rt♠q ♥tr♦t à ♣rt

Pr♦♣♦st♦♥ ❬t♦ ❪ ♦t δ ♥ ♠♣s trs sr X s ♣r♦♣rétés

s♥ts s♦♥t éq♥ts

P♦r t♦t ♣♦♥t ss p D, tr t♥♥t δ(p) ♥ p st t♥♥t à D.

Page 36: Structures de Poisson logarithmiques: invariants

♣tr r s strtrs P♦ss♦♥ ♦rt♠qs

P♦r t♦t ♣♦♥t p D, s hp st ♦♥t♦♥ é♥t♦♥ D, ♦rs δhp st

♥s é (hp)OX,p.

é♥t♦♥ ❯♥ ♠♣s trs δ st t ♦rt♠q ♦♥ D ♦ ♦

rt♠q s ér s ♦♥t♦♥s éq♥ts Pr♦♣♦st♦♥

♥ ♣♦s

DerX,p(logD) ④δ r♠ s ♠♣s trs ♦♦♠♦r♣s sr X ♥ p t q

δhp ∈ hpOX,P ⑥

DerX(logD) = ∪p∈X

DerX,p(logD)

♠♠ ♥ s ♣r♦♣rétés s♥ts

DerX(logD) st ♥ OXs♦s ♠♦ ♦ér♥t DerX .

DerX(logD) st st ♣♦r r♦t [−,−] s ♠♣s trs

♦♦♠♦r♣s

Pr ♣r♠èr ♣r♦♣rété é♦ t q DerX(logD) st ♥♦②

♠♦r♣s♠ s① ♦ér♥ts s♥t

DerX → OX/hOX

δ 7→ δh.

①è♠ ♣r♦♣rété st rt

♠♠ s♥t étt ♥ ♥ ♥tr s s ♦r♠s ér♥ts ♦rt

♠qs t s ♠♣s trs ♦rt♠qs

♠♠ ❬t♦ ❪

éré ♥ ♦r♠ ♦rt♠q s♥t ♥ ♠♣ tr

♦rt♠q st ♥ ♦r♠ ♦rt♠q

♦♥trt♦♥ ♥ ♦r♠ ♦rt♠q ♣r ♥ ♠♣ trs ♦rt

♠q st ♥ ♦r♠ ♦rt♠q

♥ ♣rtr ♦♥trt♦♥ ♥t ♥ té ♥tr DerX,p(logD) t

Ω1X,p(logD) ♣♦r t♦t p ∈ D.

s♥st ss q ΩX,p(logD) t DerX,p(logD) s♦♥t s OX,p♠♦s ré①s

♥ é♥ér ΩX,p(logD) tDerX,p(logD) ♥ s♦♥t rs q sD ér s ②♣♦tèss

té♦rè♠ ♥s ❬t♦ ❪

é♥t♦♥ ❯♥ sr rét D X st t r ♦ t♦ s DerX,p(logD)

st r ♥ t♦t p ∈ D.

①♠♣ ♥ ♦♥sèr sr X = C3 sr D = h = 0 ♦ù h = xy(x+

y)(y+xz) s ♠♣s trs δ1 = x∂x+y∂y, δ2 = x2∂x−y2∂y−z(x+y)∂zt δ3 = (xz + y)∂z ér♥t δ1(h) = 4f, δ2(h) = (2x − 3y)h t δ3(h) = xh. Pr

rs δ1 ∧ δ2 ∧ δ3 = −xy(zx+ y)(y + x). ♥ ♦♥t q D st ♥ sr r

X.

Page 37: Structures de Poisson logarithmiques: invariants

❱rétés P♦ss♦♥ ♦rt♠qs

♣r♦♣♦st♦♥ s♥t ét ♥ ♥ ♥tr s ért♦♥s ♦rt♠qs ♣r♥

♣s t s ♠♣s trs ♦rt♠qs

Pr♦♣♦st♦♥ ♦t D ♥ sr X. ♦t ♠♣s tr ♦rt♠q

♦♥ D st ♥ ért♦♥ ♦rt♠q ♣r♥♣ OX .

Pr st r q t♦t ♠♣ trs sr X st ♥ ért♦♥ OX .

♦t δ ♥ ♠♣ trs ♦rt♠q ♦♥ D. ♥ s♣♣♦s q D :=

z;h(z) = 0 t q S = h1, ..., hp ♦ù h = h1.h2...hp ♣rès é♥t♦♥

δ(hi) ∈ hiOX . ♦♥ δ st ♦rt♠q ♣r♥♣ ♦♥ S. é♦rè♠ ♥♦s és♦♥s q t♦t ♦r♠ ♦rt♠q ω ♠t ♥

értr ♦r♠

gω =dh

h∧ ξ + η.

♥ ♥ ét é♥t♦♥ s♥t

é♥t♦♥ rés ♥ q♦r♠ ♦rt♠q ω st rstrt♦♥ ξ

gà D.

♥ ♥♦tr resω

é♦rè♠ s♥t rtérs s srs ♣♦r sqs ΩX(logD) st ♥♥ré

♣r s ♦r♠s r♠és

é♦rè♠ ❬t♦ ❪ ♦t (D, p) = (D1, p)∪ ...∪ (Dm, p) é♦♠♣♦st♦♥

♦ ♥ ♦♠♣♦s♥ts rréts ♥ sr D ♥ ♥ ♣♦♥t p ∈ D, t h = h1...hm s ♦♥t♦♥ é♥t♦♥

s ♦♥t♦♥s s♥ts s♦♥t éq♥ts

Ω1X,p(logD) =

m∑i=1

OX,pdhihi

+Ω1X,p

Ω1X,p(logD) st ♥♥ré ♣r s ♦r♠s r♠és

res(Ω1X,p(logD)) =

n⊕i=1

ODi,p

Di st ♥♦r♠ dimCSingDi ≤ n− 3 ♣♦r ♠

Di ⋔ Dj i 6= j; i, j = 1, ...m sr ♦♠♣é♠♥tr ♥ s♦s

♥s♠ ♠♥s♦♥ n− 3 D Di t Dj s♦♥t à r♦s♠♥ts ♥♦r♠①

♣♦r i 6= j, i, j = 1, ...,m

dimCDi ∩Dj ∩Dk ≤ n− 3 ♣♦r i 6= j 6= k 6= i i, j, k = 1, ...,m.

❯♥ r♠rq sr s ♦r♠s ér♥ts ♦rt♠qs t♠♣s trs ♦rt♠qs

♥s tt s♦s st♦♥ ♥♦s ♣♣♦rt♦♥s qqs ♣rés♦♥s sr ♥♦t♦♥

♦r♠s ér♥ts ♦rt♠qs

t♥t ♦♥♥é q ω =dy

xér

x2ω = xdy ∈ ΩX t dx2∧ω = 2xdx∧ dyx

= 2dx∧dy ∈ ΩX ♦♥ ♣t ♦♥r q

st ♦rt♠q ♦♥ sr D C2 é♥ ♣r ♦♥t♦♥ ♦♦♠♦r♣

Page 38: Structures de Poisson logarithmiques: invariants

♣tr r s strtrs P♦ss♦♥ ♦rt♠qs

h(x, y) = x2.

r éqt♦♥ gω = 2adx

x+bdx+cdy ♥ s ♦♥t♦♥s ♦♦♠♦r♣s g, a, b t c ♣♦r

s♦t♦♥

g = xc

2a+ xb = 0

♥t ♦♥ q ♠♥s♦♥ D ∩ (x, y) ∈ C2, g(x, y) = 0 st 1; ♣♦r t♦t

s♦t♦♥ (g, a, b, c) 6= (0, a, b, 0).

s♥st ♣rès ♣r♦♣rété é♦rè♠ q ♣♦r t♦ts ♦♥t♦♥s

♦♦♠♦r♣s g, a t t♦t ♦r♠ ♦♦♠♦r♣ η ts q gω = 2adx

x+ η, ♦♥

1 = dimC(D ∩ (x, y) ∈ C2, g(x, y) = 0) ≤ 2 − 2 = 0. q st sr ♦♥

ω =dy

x♥st ♣s ♥ ♦r♠ ♦rt♠q ♦♥ D ♦rsq ♦♥ s♣♣♦s q

D st é♥ ♣r ♦♥t♦♥ h = x2. ♦♥trt éq♥ s ♣r♦♣rétés

é♦rè♠ tt ♦♥trt♦♥ rést t q ♦♥t♦♥ é♥t♦♥

D ♥st ♣s rét s♥st q t ♦tr ♦♥t♦♥ rrétté D

♥s s ②♣♦tèss té♦rè♠ ❬t♦ ❪ ♥s t♦t q st ♥♦s

s♣♣♦sr♦♥s q ♦♥t♦♥ é♥t♦♥ D st à rré r éqt♦♥ ♦

hp = 0 ♥ t♦t ♣♦♥t p ∈ D.

é♥t♦♥ t ♣r♠èrs ♣r♦♣rétés

♦t X ♥ rété ♦♠♣① ♠♥s♦♥ ♥ n t D ♥ sr rét t r

X éqt♦♥ h = 0 ♦ù h st r♠ ♥ ♦♥t♦♥ ♦♦♠♦r♣ ♥ ♥♦t OX

s s r♠s ♦♥t♦♥s ♦♦♠♦r♣s sr X.

é♥t♦♥ ❯♥ strtr P♦ss♦♥ ♦♦♠♦r♣ sr X st ♦♥♥é ♥ r♦

t −,− q ss♥ à ♥ ♦♣ (f, g) r♠s ♦♥t♦♥s ♦♦♠♦r♣s ♥ ♥

♣♦♥t x X ♥ r♠ f, g ♦♥t♦♥ ♦♦♠♦r♣ ♥ x ér♥t s ♣r♦♣rétés

s♥ts

• −,− st ♥ér ♥ts②♠étrq

• f, g, h+ g, h, f+ h, f, g = 0 ♥tté ♦

• f, gh = f, gh+ f, hg rè ♥③

st ♣r♦é ♥s ❬P♦s ❪ q t♦t strtr P♦ss♦♥ ♦♦♠♦r♣

♥t ♥ ♦♠♦♠♦r♣s♠ OX ♥ér

H : ΩX → DerX

t q H(df)(g) = f, g H st ♣♣t♦♥ ♠t♦♥♥♥ ss♦é à −,− tt ♣♣t♦♥ ♦♥ ♠♦♥tr q t♦t strtr P♦ss♦♥ ♦♦♠♦r♣

♥t ♥ t♥sr ♦♦♠♦r♣

π ∈ H0(X,2∧TX)

♣♣é tr P♦ss♦♥

Page 39: Structures de Poisson logarithmiques: invariants

❱rétés P♦ss♦♥ ♦rt♠qs

é♥t♦♥ ❯♥ strtr P♦ss♦♥ ♦♦♠♦r♣ −,− sr X st t ♦

rt♠q ♦♥ D s ♣♦r t♦t r♠ f ♦♥t♦♥ ♦♦♠♦r♣ ♠♣

♠t♦♥♥ ss♦é H(df) st ♥ st♦♥ DerX(logD)

♥s st t♦t rété P♦ss♦♥ ♦♦♠♦r♣ ♦rt♠q ♦♥ ♥

sr D sr ♣♣é s♠♣♠♥t rété P♦ss♦♥ ♦rt♠q t ♦♥ ♥♦tr

(X, −,−, D).

é♦ tt é♥t♦♥ q ♣♦r t♦t ♦rt U X t t♦t st♦♥ f

OX sr U f,− st ♥ ért♦♥ ♦rt♠q ♣r♥♣ ♦♥ é

é♥t♦♥ D.

Psq D st r é♦rè♠ ♥s ❬t♦ ❪ ♥tr♥ q

n∧ Ω1

X(logD) = ΩnX(logD).

t

DeriX(logD) :=i∧Der1X(logD).

♥s s ♦♥

ΩqX(logD) =q∧Ω1

X(logD) ∼= HomOX(q∧Der1X(logD),OX)

é♥t♦♥ ♦t D ♥ sr r X.

s st♦♥s q∧Der1X(logD) s♦♥t ♣♣és q♠♣s trs ♦rt♠qs

♥ ♣♦s erX(logD) :=n⊕i=1DeriX(logD)

[−,−]s és♥ r♦t ♦t♥ ♦rs ♦♠♣t t♥ t qDerX(logD)

st st ♣♦r r♦t s ♠♣s trs erX(logD) rst st

♣♦r [−,−]s.

é♥t♦♥ ♥ ♣♣ r♦t ♦t♥ ♥s ♦rt♠q ♦♥ ♥

sr r D rstrt♦♥ [−,−]s à erX(logD).

s♥st q♥ tr ♦♦♠♦r♣ ♦rt♠q π st P♦ss♦♥ s t s♠♥t

s s♦♥t r♦t ♦t♥ ♦rt♠q st ♥

♦r♦r tr P♦ss♦♥ t♦t strtr P♦ss♦♥ ♦rt

♠q sr X st ♥ st♦♥ Der2X(logD)

Pr ♦t π tr ♥ strtr P♦ss♦♥ ♦rt♠q sr X, ♦rs

♣♦r t♦t a, b ∈ OX , ♦♥

π(da, db) := H(da)b

stàr idaπ ∈ Der1X(logD).

♥ ét ♣r♦♣rété ♥rs ♦♣ (ΩX , d) q DerX ∼=σHom(ΩX ,OX).

♦♠♣t t♥ t q ΩX ⊂ ΩX(logD) ♦rs Hom(ΩX(logD),OX) ⊂Hom(ΩX ,OX). Pr rs ♥s♦♥ Der1X(logD) ♥s DerX ♠♣q q

Page 40: Structures de Poisson logarithmiques: invariants

♣tr r s strtrs P♦ss♦♥ ♦rt♠qs

Hom(ΩX(logD),OX) ∼= Der1X(logD) ∼= σ(Der1X(logD)). ♥s H ♥t ♥

♦♠♦♠♦r♣s♠ ΩX rs Hom(ΩX(logD),OX); r♥r s ♣r♦♦♥ ♦♥

♠♥èr ♥♦♥q ♥ ♥ ♦♠♦♠♦r♣s♠ s① OX ♠♦s H

ΩX(logD) rs Hom(ΩX(logD),OX). ♦ù réstt

♦r♦r ♦t strtr P♦ss♦♥ ♦♦♠♦r♣ ♥♦♥ tr t ♥♦♥ s②♠

♣tq sr ♥ sr ss st ♦rt♠q

Pr

♦s s♦♥s q t♦t strtr P♦ss♦♥ ♦♦♠♦r♣ ♥♦♥ ♥ sr X st ♥t

♣r ♥ st♦♥ π ré ♥t♥♦♥q ω−1X X. Psq π st ♥♦♥ s②♠♣tq

①st ♥ ♦♥t♦♥ ♦♦♠♦r♣ h t qD := z ∈ X,h(z) = 0 t π = h∂x∧∂y. s♥st q π st ♦rt♠q ♦♥ D.

①♠♣ ♦t D = h = x4 + y5 + xy4 = 0 ♥ ♦r ♣tq

X = C2. s ♠♣s trs δ1 = (16x2 + 20xy)∂x + (12xy + 16y2)∂y t

δ2 = (16xy2 + 4y3 − 12xy)∂x + (12y3 − 4x2 + 5xy − 100y2)∂y s♦♥t ♦rt♠qs

♦♥ D s s♦♥t rs t ♦♥stt♥t ♦♥ ♥ s DerX(logD). q

♠♣q q D st r ♥ é♥t sr C2 r♦t P♦ss♦♥ s♥t

f, g = −(64x4 + 1356x2y2 + 64xy4 + 1808xy3 + 64y5)(∂xf∂yg − ∂yf∂xg).

r♦t st P♦ss♦♥ ♦rt♠q ♦♥ D.

♥ t

f, g =

= [(16x2 + 20xy)(12y3 − 4x2 + 5xy − 100y2)− (16xy2 + 4y3 − 12xy)(12xy + 16y2)]

(∂xf∂yg − ∂yf∂xg)

=

∣∣∣∣16x2 + 20xy 12xy + 16y2

16xy2 + 4y3 − 12xy 12y3 − 4x2 + 5xy − 100y2

∣∣∣∣ (∂xf∂yg − ∂yf∂xg)

= hk(∂xf∂yg − ∂yf∂xg)

♦ù

hk =

∣∣∣∣16x2 + 20xy 12xy + 16y2

16xy2 + 4y3 − 12xy 12y3 − 4x2 + 5xy − 100y2

∣∣∣∣ .

①st♥ k st ssré ♣r t q D st r

s♥st q ♣♦r t♦t ♦♥t♦♥ ♦♦♠♦r♣ f, f,− = kh(∂xf∂y − ∂yf∂x) r

kh(∂xf∂y − ∂yf∂x) ∈ DerX(logD). ♥ ♦♥t q tt strtr P♦ss♦♥ st

♦rt♠q ♦♥ D.

①♠♣ ♥ ♦♥sèr sr X = C3 r♦t f, g = (zx+y)(x(∂xf∂zg−∂zf∂xg)−y((∂yf∂zg−∂zf∂yg)). ♦♥tr♦♥s q st P♦ss♦♥ ♦rt♠q ♦♥

sr D = h = xy(x+ y)(y + xz) = 0 X = C3.

t♥sr ss♦é à r♦t st

π = x(zx+ y)∂x∧ ∂y+ y(xz+ y)∂y ∧ ∂z. P♦r ♠♦♥trr q −,− st P♦ss♦♥

st ♠♦♥trr q

πhi∂hπjk+πhj∂hπki+πhk∂hπij = 0 ♣♦r t♦s i, j, k = 1, 2, 3 ♦ù (πij) st ♠tr

π. ♥s s ♣rtr s étés s♦♥t éq♥ts à

Page 41: Structures de Poisson logarithmiques: invariants

❱rétés P♦ss♦♥ ♦rt♠qs

z, x∂zy, z+ z, y∂zz, x = 0. q st éré

♦s ♣♦♦♥s ss r♠rqr q D st r r s ♠♣s trs δ1 =

x∂x + y∂y δ2 = x2∂x − y2∂y − z(x + y)∂z t δ3 = (xz + y)∂z ♦r♠♥t ♥ s

DerX(logD) t q π = δ1 ∧ δ3. ♥ ♣t ♦♥ r r♦t ♦t♥

♦rt♠q π. r r♦t ♥♦s ♦♥♥ [δ1 ∧ δ3, δ1 ∧ δ3] = [δ1, δ1] ∧ δ3 ∧δ3 + δ ∧ [δ1, δ3] ∧ δ3 + δ ∧ [δ3, δ1] ∧ δ3 + δ1 ∧ δ1 ∧ [δ3, δ3] = 0. q ♠♦♥tr q

r♦t st P♦ss♦♥ rst à ♠♦♥trr q st ♦rt♠q ♦♥ D.

P♦r st r♠rqr q ♣♦r t♦t ♦♥t♦♥ ♦♦♠♦r♣ sr X, ♦♥

f,− = δ1(f)δ3 − δ3(f)δ1 q st ♦rt♠q ♦♥ D.

❱rétés ♦s②♠♣tqs

♥s tt ♣rt D és♥r ♥ sr r ♥ rété ♦♠♣① X

♠♥s♦♥ ♦♠♣① n t ω és♥r ♥ ♦r♠ ♦rt♠q ♦♥ D

r♠é ♥ ♦♥sèr ♠♦r♣s♠ s① I : DerX(logD) −→ ΩX(logD)

é♥ ♣r

I(v) = ivω.

P♦r t♦t v ∈ DerX(logD), ♦♥ ♥♦t Lvω éré ω s♥t v.

é♥t♦♥ ❯♥ st♦♥ v DerX(logD) st t ω♦s②♠♣tq s

♣résr ω Lvω = 0.

♥s♠ s ♠♣s ω♦s②♠♣tqs sr ♥♦té SympωX ♣r♦♣♦st♦♥ s

♥t ♦♥♥ ♥ rtérst♦♥ s r♠s ♠♣s ω♦s②♠♣tqs

Pr♦♣♦st♦♥ ❯♥ ♠♣ trs ♦rt♠q v st ω

♦s②♠♣tq s t s♠♥t s ivω st ♥ ♥ ♦r♠ ♦rt♠q r

♠é

♦t α r♠ ♦r♠ ♦rt♠q sr X. ①st v ∈ SympωX t

q α = I(v) ♦rs iwα = 0 ♣♦r t♦t w ∈ ker(I).

Pr t♥t ♦♥♥é q dω = 0 ♦rs

Lv(ω) = ivdω + divω = d(I(v))

è ♣r ♣r♠èr ♣r♦♣rété

P♦r q st ①è♠ ♣r♦♣rété ♦♥ ♣♦r t♦t w ∈ ker(I)

iwα = α(w)

= I(v)(w)

= ω(v, w)

= −ω(w, v)= −I(w)(v) = 0

Page 42: Structures de Poisson logarithmiques: invariants

♣tr r s strtrs P♦ss♦♥ ♦rt♠qs

é♥t♦♥ ❯♥ ♠♣ trs ♦rt♠q v st t ω♠t♦♥♥ s ①

st ♥ ♦♥t♦♥ ♦♦♠♦r♣ f sr X t q I(v) = df

❯♥ t ♦♥t♦♥ ♦rsq ①st st ♣♣é ω♠t♦♥♥♥ v.

♣r Pr♦♣♦st♦♥ ♥♦s és♦♥s q s ♠♣s ω♠t♦♥♥s

s♦♥t ωs②♠♣tqs

és♥♦♥s ♣rHωX ♥s♠ s ♠♣s ω♠t♦♥♥s t ♣rH1(X, logD) ♣r

♠r r♦♣ ♦♦♠♦♦q ♠ ♦rt♠q X. ♥ ♣r♦♣♦st♦♥

s♥t

Pr♦♣♦st♦♥ st 0 → HωX → SympωX → H1(X, logD) st

①t

♦rsq D st ♦♠♥t qs♦♠♦è♥ t (X−D) ♣r♦♠♣t tt st

♥t

0 → HωX → SympωX → H1(X −D,C)

Pr ♣r♠èr ♣r♦♣rété é♦ t q i[v,w]ω = d(iv(dg)) ♣♦r t♦t

v, w ∈ HωX ts q I(v) = df t I(w) = dg. ①è♠ ♣r♦♣rété q♥ à

é♦ é♦rè♠ r♦t♥ ♠ t é♦rè♠ ♦♠♣rs♦♥

♦rt♠q

①♠♣ P♦r D := (0, z2, z3) ∈ C3, ♦♥

v = v1z1∂z1 + v2∂z2 + v3∂z3 ∈ DerX(logD).

Pr rs ω =dz1z1

∧ dz2 +dz1z1

∧ dz3 ∈ ΩC3(logD) dω = 0 t I(v) = −(v2 +

v3)dz1z1

+ v1d(z2 + z3). ♥ ♣r♥♥t v1 = 0 t v2 + v3 = −1 v rst ♥ ♠♣

trs ♦rt♠q ♦♥ D t ♦♥ I(v) =dz1z1

= d log z1 Psq ♦♥t♦♥

(z1, z2, z3) 7→ log z1 ♥st ♣s ♦♦♠♦r♣ sr C3, ♦rs v = v2∂z2 − (1 + v2)∂z3 ♥st

♣s ♥ ♠♣ ω♠t♦♥♥

♥ ♣♦s K = ker(I).

ω st r♥ ♦♥st♥t t ♥♦♥ tr s ♦♥t♦♥s ω♠t♦♥♥♥s ①st♥t

♦♠♥t ♥ ♣t ♦♥ ♥tr♦r s s r♠s ♦♥t♦♥s ♦♠♥t

ω♠t♦♥♥♥s

és♥♦♥s ♣r OX/K s♣ s ♦♥t♦♥s ♦♠♥t ω♠t♦♥♥♥s

Pr♦♣♦st♦♥ OX/K st ♥ s èrs P♦ss♦♥

Pr ♦♥t f, g ∈ OX/K ; ①st v, w ∈ DerX(logD) ts q df = I(v) t

dg = I(w) r d(fg) = fdg + gdf = fI(w) + gI(v) = I(fw + gv). ♦♥ OX/K st

♥ s♦s èr OX . ♣rès é♥t♦♥ OX/K , ♣♣t♦♥ ϕ : v 7→ f ♦ù

df = I(v) st ♥ srt♦♥ OX/K sr HωX

Page 43: Structures de Poisson logarithmiques: invariants

❱rétés P♦ss♦♥ ♦rt♠qs

①st ♥ ♣♣t♦♥ ψ : OX/K → HωX t q ϕ ψ = idOX/K

♥ ♦♥sèr ♣♣t♦♥ ♥ér

−,−ω : OX/K ⊗OX/K → OX/K

(f, g) 7→ ψ(f)g

♣rès q ♣réè ♦♥

f, gω = ψ(f).g

= ω(w,ψ(f))

= −ω(ψ(f), w)= −iwiψ(f)ω = −iψ(g)df = −g, fω

P♦r q st ♥tté ♦ ♥♦s ♦♥s

(dω)(ψ(f), ψ(g), ψ(h)) = ψ(f)ω(ψ(g), ψ(h)) − ψ(g)ω(ψ(f), ψ(h)) +

ψ(h)ω(ψ(f), ψ(g)) − ω([ψ(f), ψ(g)], ψ(h)) + ω([ψ(f), ψ(h)], ψ(g)) −ω([ψ(g), ψ(h)], ψ(f))

r−ω([ψ(f), ψ(g)], ψ(h)) + ω([ψ(f), ψ(h)], ψ(g))− ω([ψ(g), ψ(h)], ψ(f))

= i[ψ(f),ψ(g)]ωψ(h) + i[ψ(f),ψ(h)]ωψ(g)− i[ψ(g),ψ(h)]ωψ(f)

= −d(iψ(f)dg)ψ(h) + d(iψ(f)dh)ψ(g)− d(iψ(g)dh)ψ(f)

= −d(ψ(f)dg)ψ(h) + d(iψ(f)dh)ψ(g)− d(iψ(g)dh)ψ(f)

= −d(ω(ψ(g), ψ(f)))ψ(h) + d(ω(ψ(h), ψ(f)))ψ(g)− d(ω(ψ(h), ψ(g)))ψ(f)

= −ψ(h)ω(ψ(g), ψ(f)) + ψ(g)ω(ψ(h), ψ(f))− ψ(f)ω(ψ(h), ψ(g))

= ψ(f)ω(ψ(g), ψ(h))− ψ(g)ω(ψ(f), ψ(h)) + ψ(h)ω(ψ(f), ψ(g)) .♦♥

(dω)(ψ(f), ψ(g), ψ(h)) = 2(ψ(f)ω(ψ(g), ψ(h)) − ψ(g)ω(ψ(f), ψ(h)) +

ψ(h)ω(ψ(f), ψ(g))).

♥ ♥ ét qf, gω, hω+ = −h, ψ(f)g+ = −ψ(h)(ψ(f)g)+

= −ψ(h)(ψ(f)g)− ψ(f)(ψ(g)h)− ψ(g)(ψ(h)f)

= −ψ(h)ω(ψ(g), ψ(f))− ψ(f)ω(ψ(h), ψ(g))− ψ(g)ω(ψ(f), ψ(h))

= ψ(f)ω(ψ(g), ψ(h))− ψ(g)ω(ψ(f), ψ(h)) + ψ(h)ω(ψ(f), ψ(g))

=1

2(dω)(ψ(f), ψ(g), ψ(h))

= 0r ω st r♠é

♥ ♥ ét ♦r♦r s♥t

♦r♦r (X, −,−ω, D) st ♥ rété P♦ss♦♥ ♦rt♠q

és♥♦♥s ♣r Kω s♦s s èrs K ♦r♠é s ♠♣s ♦①

♦rs ♦♥ st ①t ♦rt s① èrs s♥t

0 → Kω → HωX →

OX/K

C→ 0

Page 44: Structures de Poisson logarithmiques: invariants

♣tr r s strtrs P♦ss♦♥ ♦rt♠qs

é♥t♦♥ ♥ ♣♣ rété ♦s②♠♣tq t♦t tr♣t (X,ω,D) ♦r♠é ♥

rété ♦♠♣① ♠♥s♦♥ ♦♠♣① 2n ♥ sr rét D X t ♥

♦r♠ ♦rt♠q r♠é ω ér♥t

ωn 6= 0 ♥s H0(X,Ω2n[D])

♦rsq (X,ω,D) st ♥ rété ♦s②♠♣tq st ♥t

0 → CX → OX → HωX → 0

Pr rs t♦t st♦♥ s : HωX → OX ①t♥s♦♥ ♥t ♥ ♦r♠

C : ∧2HωX → C

é♥ ♣r

C(v, w) = [s(v), s(w)]− s([v, w])

q st ♥ ♦② ②♥r ♦s ♦♥s ♠♦♥trr q st ♥s

ss ♦♦♠♦♦ ω.

Pr♦♣♦st♦♥ C t ω ♦♥t ♠ê♠ ss ♦♦♠♦♦

Pr ♣♣♦♥s q st qst♦♥ tr♦r ♥ ♥ ♥tr ♦r♠ C sr HωX

♥t ♣r t♦t st♦♥ ♥ér s ①t♥s♦♥ èr HωX s ♠♣s

trs ♦♠♥t ♦♠t♦♥♥s t ♦r♠ ♦s②♠♣tq ω sr rété

♦s②♠♣tq X.

Ps ♣résé♠♥t ①t♥s♦♥ st ♦♥♥é ♣r

0 → CXi→ OX

χ→ HωX → 0

♦ù iχfω = df ♣♦r t♦t f ∈ OX .

♣♣♦♥s ss q strtr P♦ss♦♥ ♥t ♣r ω st é♥ ♣r

f, g = −ω(χf , χg).

♣♣t♦♥

θ : HωX → End(OX)

X 7→ θ(X) : f 7→ s(X), f

♥t sr OX ♥ strtr HωX ♠♦

♥ t ♣♦r t♦t X,Y ∈ HωX , ♦♥

θ([X,Y ])f

= s(X), s(Y ), fJacobi= s(X), s(Y ), f − s(Y ), s(X), f= [θ(X), θ(Y )]f.

Page 45: Structures de Poisson logarithmiques: invariants

❱rétés P♦ss♦♥ ♦rt♠qs

♣rés♥t ♣♦s♦♥s Lalt∗(HωX ,OX) ♥s♠ s ♣♣t♦♥s ♠t♥érs

tr♥és sr HωX rs ♥s OX .

Lalt∗(HωX ,OX) ♠♥ ér♥t ②♥r δ é♥ ♣r

δf(X1, ..., Xp) =∑

(−1)i+1θ(Xi)f(X1, ..., Xi, ..., Xp)+∑(−1)i+jf([Xi, Xj ], X1, ..., Xi, ..., Xj , ..., Xp)

st ♥ ♦♠♣① ♥s ♦♥t s r♦♣s ♦♦♠♦♦s ss♦és s♦♥t ♥♦tés

H∗(HωX ,OX).

P♦r p = 1, 2, été ♦♥♥

δf1(X1, X2) = θ(X1)f1(X2)− θ(X2)f

1(X1)− f1([X1, X2])

♣♦r t♦t f1 ∈ Lalt1(HωX ,OX) t

δf2(X1, X2, X3) =

= θ(X1)f2(X2, X3)− θ(X2)f

2(X1, X3) + θ(X3)f2(X1, X2)−

f2([X1, X2], X3) + f2([X1, X3], X2)− f2([X2, X3], X1)

♣♦r t♦t f2 ∈ Lalt2(HωX ,OX).

s st♦♥s ♥érs ①t♥s♦♥ ét♥t s ♣♣t♦♥s C♥érs HωX

rs OX , s s♦♥t ♦♥ s ♦♥s ♦t s ♥ st♦♥ ♣rès

♦♥

δs(X1, X2) = θ(X1)s(X2)− θ(X2)s(X1)− s([X1, X2])

= fX1 , s(X2) − fX2 , s(X1)s([X1, X2])

= −ω(χ(fX1), χ(s(X2))) + ω(χ(fX2), χ(s(X1)))− s([X1, X2])

.

♥s

δs(X1, X2) + ω(X1, X2) = −ω(X1, X2)− s([X1, X2]).

r

C(X1, X2) = s(X1), s(X2) − s([X1, X2]) = −ω(X1, X2)− s([X1, X2])

s étés t ♦♥ ét q

C = ω + δs.

Pr rs ♥ r♠♣ç♥t f2 ♥s ♣r ω t ♥ ♣♣q♥t t q χ st

♥ ♠♦r♣s♠ èrs ♦♥ ♦t♥t

δω = 0.

♦ù réstt

♦t ω =dh

h∧ ψ + η ♥ ♦r♠ ♦s②♠♣tq sr X.

♥ ♣♦s

SD = δ ∈ DerX(logD), ψ.δ = 0.♥

Page 46: Structures de Poisson logarithmiques: invariants

♣tr r s strtrs P♦ss♦♥ ♦rt♠qs

♠♠ P♦r t♦t rété ♦s②♠♣tq (X,D, ω), SD st ♥ s♦s

èr DerX(logD)

Pr ♦t ω =dh

h∧ψ+η ♥ ♦r♠ ♦s②♠♣tq sr X. ♥ 0 = dω = dψ.

r

0 = dψ(x, y) = X.ψ(ω)(Y )−X.ψ(Y )− ψ([X,Y ]).

♦ù réstt

és♥♦♥s ♣r Dsing ♣rt s♥èr D t ♣r Dred s ♣rt ss

♦r♦r SD st ♥ strt♦♥ ♥tér X à s ♠♥s♦♥

♥ sr Dred.

qs ①♠♣s rétés P♦ss♦♥ ♦rt♠qs

♥ s♣♣♦s q X st ♥ rété ♦♠♣① D ♥ sr rét t r

X. ♦s tt ②♣♦tès ΩX(logD) rs♣ DerX(logD) ♣t êtr ♦♠♠

s s st♦♥s ♥ ré t♦r T ∗(logD) rs♣ T (logD) T ∗(logD) rs♣

T (logD) st ♣♣é ré ♦t♥♥t t♥♥t ♦rt♠q X. ♥ s ♦♥♥

θ ∈ H0(X,∧2 T (logD)).

Pr é♥t♦♥ θ st ♥ ♣♣t♦♥ OX ♥ér ♥ts②♠étrq sr T ∗(logD).

♦s s♦♥s q ♣♦r t♦t A♠♦M s ♦♥trsM⊗− t (−)M s♦♥t ♦♥ts

♥ tr ♣♦r t♦t R♥♥ A ♥ ♣r♦♣♦st♦♥ s♥t

Pr♦♣♦st♦♥

HomOX(T ∗(logD))⊗ T ∗(logD)),OX) ≃ HomOX

(T ∗(logD)), T (logD))

Pr ♦♥sérr s♦♠♦r♣s♠ ♦♥t♦♥ ♦♥t♦r t tsr té ♥

tr T ∗(logD) t T (logD)

Pr♦♣♦st♦♥ ♥t q s ♦♥♥r ♥ tr ♦rt♠q π st

éq♥t à s ♦♥♥r ♥ ♥q ♠♦r♣s♠ π : T ∗X(logD) → TX(logD) r♥♥t

♦♠♠tt r♠♠ s♥t

OT ∗X(logD)X ⊗ T ∗

X(logD)ev

T∗X (logD)

OX // OX

T ∗X(logD)⊗ T ∗

X(logD)

π×idT∗X

(logD)

OO

π

77n

nn

nn

nn

nn

nn

nn

nn

nn

nn

nn

nn

nn

nn

n

♥ t♥♥t ♦♠♣t é♥t♦♥ evT ∗X(logD)

OX(π) ♦♠♠ttté

r♠♠ ♠♦♥tr q π st é♥ ♣r éqt♦♥ s♥t

〈π(α), β〉 = 〈π, α ∧ β〉

Page 47: Structures de Poisson logarithmiques: invariants

❱rétés P♦ss♦♥ ♦rt♠qs

P♦r t♦t α, β ∈ T ∗X(logD).

Pr♦♣♦st♦♥ ♦t X ♥ rété ♦♠♣① t D ♥ sr rét t r

X ré ♦t♥♥t ♦rt♠q T ∗X(logD) st ♦s②♠♣tq sr π∗(D) st

♦♥ ♥ rété P♦ss♦♥ ♦rt♠q

Pr ♥ t s F : (X1, D1) → (X2, D2) st ♥ ♠♦r♣s♠ rétés ♦♠

♣①s t q F ∗(D2) = D1 ♦rs r♠♠ ♣r♦t ré s♥t ♥t ♥

♦♠♦♠♦r♣s♠

ϕF : X1 ×X2 T∗X logD2 → T ∗

X logD1

T ∗ logD1

X1 ×X2 T∗ logD2

ϕF=F ∗p244

p2 //

p1

T ∗ logD2

π2

F ∗

OO

X1 F// X2

.

♥ ♣♦s♥t ♥s r♠♠ X1 = T ∗(logD) t X2 = X ♦♥ ♦t♥t ♣r s

♣♣t♦♥ ♦♥ ∆ : T ∗(logD) → T ∗(logD) ×X T ∗(logD) r♠♠

♦♥♥♥t à ♥ ♠♦r♣s♠ s① θ = ϕπ ∆

T ∗X(logD)

θ //

T ∗T ∗X(logD)(log π

∗(D))

T ∗X(logD)×X T ∗

X(logD)

ϕπ=π∗p233

p2 //

p

T ∗X(logD)

π

π∗T∗

X(logD)

OO

T ∗X(logD) π

// X

.

♣r ♦♥strt♦♥ θ ∈ H0(T ∗X(logD),Ω1

T ∗X(logD)(log(π

∗(D))) ♥ ♣♦s ω = dθ

Pr ♦♥strt♦♥ ω st ♥ ♦r♠ ♦s②♠♣tq

♦r♦r ❬t♦ ❪ ♦t D ♥ sr à r♦s♠♥ts ♥♦r♠① X.

♦♣ (T ∗X(logD), π∗(D)) st ♥ rété ♦s②♠♣tq

Pr ♦t (U0, x0) ♥ rt ♦ ♦rt♠q X ♥ x0. ①st ♥ t

♥ s ♠ ♦♥t♦♥s ξi; i = 1, ..., n ♦♦♠♦r♣s é♥s sr π∗(U0) ts

q

θ|π∗(U0) =

p∑

i=1

ξidxixi

+

n∑

i=p+1

ξidxi

Page 48: Structures de Poisson logarithmiques: invariants

♣tr r s strtrs P♦ss♦♥ ♦rt♠qs

①♠♣ ❬♦t♦ ❪ X st ♥ sr ♦♠♣① ♠♥ ♥

sr rét D t s [D] st ss ♥t♥♦♥q K∗X , ♦rs ♦♣ (X,D)

st ♥ rété ♦s②♠♣tq t ♣s ♦r♠ ♦s②♠♣tq ss♦é st

ω ∈ K([D]) ⋍ OX .

é♥t♦♥ ♥ ♣♣ ♦r♠ ♦♠ ♦rt♠q ♦♥ ♥ sr rét

t r D ♥ rété ♦♠♣① X ♠♥s♦♥ n t♦t st♦♥ s♥s ③ér♦s

ΩnX(logD)

♣rès é♦rè♠ ♥s ❬t♦ ❪ s ♦r♠s ♦♠s ♦rt♠qs s♦♥t

♦r♠

µ =1

hdz1 ∧ dz2 ∧ ... ∧ dzn

Pr♦♣♦st♦♥ ♦t D = h = 0 ♥ sr r ♥ rété ♦♠♣①

X ♠♥s♦♥ α ♥ ♦r♠ ♦♦♠♦r♣ r♠é X t µ ♥ ♦r♠ ♦♠

♦rt♠q X. ♦rs t♦t tr π X t q

iπµ = α

st P♦ss♦♥ ♦rt♠q ♦♥ D.

Pr ♦t a ♥ ♦♥t♦♥ ♦♦♠♦r♣ ♥ s♥♥♥t ♣s sr X. ♥ ♣♦s

µ =a

hdx ∧ dy ∧ dz, α = αxdx+ αydy + αzdz

Pr ♥ rt ♦♥ ♦t♥t

π =h

a(αz∂x ∧ ∂y + αy∂z ∧ ∂x + αx∂y ∧ ∂z)

P♦r ♠♦♥trr q π st P♦ss♦♥ st érr ♥tté ♦ q ♥s

s s rés♠ à

π12(∂yπ23 − ∂xπ31) + π13(∂zπ23 − ∂yπ12) + π23(∂zπ31 − ∂xπ12) = 0

♦ù π12 = ha−1αz, π13 = −ha−1αy t π23 = ha−1αx.

r

π12(∂yπ23 − ∂xπ31) = h2a−1αz(αx∂ya−1 − αy∂xa

−1) + ha−2αz(αx∂yh − αy∂xh) +

a−2h2αz(∂yαx − ∂xαy)

π13(∂z(π31)−∂x(π12)) = h2a−1αy(αz∂xa−1−αx∂za−1)+ha−2αy(αz∂xh−αx∂zh)+

h2a−2αy(∂xαz − ∂zαx)

π23(∂z(π31)−∂y(π12)) = h2a−1αx(αy∂za−1−αz∂ya−1)+ha−2αx(αy∂zh−αz∂yh)+

a−2h2αx(∂zαy − ∂yαz)

t dα = 0 s t s♠♥t s

∂yαx − ∂xαy = ∂xαz − ∂zαx = ∂zαy − ∂yαz = 0

Page 49: Structures de Poisson logarithmiques: invariants

s♣ s SU(2) ♠♦♥♦♣ôs ♠♥étqs r

q ♠♦♥tr q π st ♥ t♥sr P♦ss♦♥ Pr rs ♣♦r t♦t st♦♥ f

OX ♦♥

f,− = a−1h[(∂xfαz − ∂zfαx)∂y + (∂zfαy − ∂yfαz)∂x + (∂yfαx − ∂xfαy)∂z]

st ♥ ért♦♥ ♦rt♠q ♦♥ hOX .

s♣ s SU(2) ♠♦♥♦♣ôs ♠♥étqs r

♣rès ♦♥s♦♥ ♥s ❬♦♥s♦♥ ❪ s♣ ♠♦ ér M2 s

♠♦♥♦♣ôs ♠♥étqs r st ♥ t♦♥ rété ♦♠♣① R2

s ♦♥t♦♥s rt♦♥♥s w(z) =f(z)

g(z) ré ts q w(∞) = 0.

♥ ét♥t ②♥♠q s ♠♦♥♦♣ôs ♦♥ ♣r♦ ♥s

❬t② t♥ ❪ q s β1 t β2 s♦♥t s r♥s g, ♦rs

ω =1

f(β1)f(β2)(f(β2)df(β1) ∧ dβ1 + f(β1)df(β2) ∧ dβ2)

st ♥ strtr s②♠♣tq sr M2.

♦s ♦♥s ♠♦♥trr q ω st ♥ ♦r♠ ♦s②♠♣tq ♦♥ D =

R(f, g) = 0 ♦ù R(f, g) és♥ rést♥t f t g. Pr st ♥♦s ♦♥strs♦♥s

strtr P♦ss♦♥ ♥t ♣r ω t ♥♦s ♠♦♥tr♦♥s q st ♦rt♠q

♦♥ D.

♣rès ❬♦♥s♦♥ ❪ s éé♠♥ts R2 s♦♥t s♦s ♦r♠

f(z)

g(z)=

a0 + a1z

b0 + b1z + z2

r w(∞) = 0. ♥s s

w(z) =f(z)

g(z)=

a0 + a1z

b0 + b1z + z2

t ♦♥

g= b21 − 4b0, β1 = −1

2

(b1 +

√g

), β2 =

1

2

(−b1 +

√g

).

♥ ♥ ét q

dβ1 =1√g

(β1db1 + db0) , dβ2 = − 1√g

(β2db1 + db0)

df(β1) ∧ dβ1 =1√g

(β1da0 ∧ db1 + da0 ∧ db0 + β21da1 ∧ db1 + β1da1 ∧ db0

)

df(β2) ∧ dβ2 = − 1√g

(β2da0 ∧ db1 + da0 ∧ db0 + β22da1 ∧ db1 + β2da1 ∧ db0

).

Page 50: Structures de Poisson logarithmiques: invariants

♣tr r s strtrs P♦ss♦♥ ♦rt♠qs

♥ ♣♦s

ω =df(β1)

f(β1)∧ dβ1 +

df(β2)

f(β2)∧ dβ2.

Psq f t g ♥♦♥t ♣s r♥s ♦♠♠♥s ω st ♥ é♥ sr C4. ♥s

s ①♣rss♦♥ ♥t

√gf(β1)f(β2)ω

= (β1f(β2)− β2f(β1)) da0 ∧ db1 + (f(β2)− f(β1)) da0 ∧ dbo+

(β21f(β2)− β22f(β1)

)da1 ∧ db1 + (β1f(β2)− β2f(β1)) da1 ∧ db0.

r

f(β1)f(β2) = (a0 + a1β1)(a0 + a1β2) = a20 + a1a0(β1 + β2) + a21β1β2= a20 − a1a0b1 + a21b0.

β1f(β2)− β2f(β1) = −a0√g

β21f(β2)− β22f(β1) = (a0b1 − a1b0)√g

f(β2)− f(β1) = a1√g.

Pr rs ∣∣∣∣∣∣

a0 a1 0

0 a0 a1b0 b1 1

∣∣∣∣∣∣= a20 − a1a0b1 + a21b0.

s♥st q R(f, g) = f(β1)f(β2). ♥s st ♥♦s ♥♦tr♦♥s R.

♥ sstt♥t s ①♣rss♦♥s ♥s ♦♥ ♦t♥t

ω =1

R(−a0da0 ∧ db1 + a1da0 ∧ db0 + (a0b1 − a1b0)da1 ∧ db1 − a0da1 ∧ db0) .

♥ ♥ ét q

R2ω ∧ ω= (−a0da0 ∧ db1 + a1da0 ∧ db0 + (a0b1 − a1b0)da1 ∧ db1 − a0da1 ∧ db0)∧ (−a0da0 ∧ db1 + a1da0 ∧ db0 + (a0b1 − a1b0)da1 ∧ db1 − a0da1 ∧ db0)= 2

(a20da0 ∧ db1 ∧ da1 ∧ db0 + a1(a0b1 − a1b0)da0 ∧ db0 ∧ da1 ∧ db1

)

= 2(a20 − a1(a0b1 − a1b0)

)da0 ∧ da1 ∧ db0 ∧ db1

= 2Rda0 ∧ da1 ∧ db0 ∧ db1.

♦ù

ω ∧ ω =2

Rda0 ∧ da1 ∧ db0 ∧ db1 6= 0.

♥ ♦♥t q ω st ♥ ♦r♠ ♦s②♠♣tq ♦♥ D := R = 0. r♦t P♦ss♦♥ ss♦é à ω st

u, vω = f(β1)

(∂u

∂β1

∂v

∂f(β1)− ∂u

∂f(β1)

∂v

∂β1

)+f(β2)

(∂u

∂β2

∂v

∂f(β2)− ∂u

∂f(β2)

∂v

∂β2

).

Page 51: Structures de Poisson logarithmiques: invariants

s♣ s SU(2) ♠♦♥♦♣ôs ♠♥étqs r

s♥st q ♠♣ ♠t♦♥♥ ss♦é à u st

Xu = f(β1)

(∂u

∂β1

∂f(β1)− ∂u

∂f(β1)

∂β1

)+ f(β2)

(∂u

∂β2

∂f(β2)− ∂u

∂f(β2)

∂β2

).

♥ ♣♣q♥t ♠♣ sr R = f(β1)f(β2), ♦♥ ♦t♥t

Xu(R) = R

(∂u

∂β1+

∂u

∂β2

).

♦♠♠ Xu(R) st ♥ éé♠♥t é ♥♥ré ♣r R, ♦♥ ♦♥t q −,−ωst ♥ strtr P♦ss♦♥ ♦rt♠q ♦♥ D.

tr sr D = R(f, g) = 0.♣rès q ♣réè srD ♣♦r éqt♦♥ x2−xyt+y2z. ♥ r♠rq

q

x2 − xyt+ y2z = (x− yt

2)2 + y2(z − t2

4)

= X2 + Y 2Z

♦ù X = x− yt

2, Y = y t Z = z− t2

4. Pr rs X

∂h

∂X+Y

∂h

∂Y= 2h. ♥ ♥ ét

s②stè♠ ♠♥♠ é♥értrs s♥t Der(logD).

δ1 = X∂

∂X+ Y

∂Y

δ2 = Y∂

∂Y+ 2Z

∂Z

δ3 = Y 2 ∂

∂X+ 2X

∂Z

δ4 = Y Z∂

∂X−X

∂Y

Psq Der(logD) st ♥ s♦s ♠♦ Der q st r♥ ♥ ♣t êtr

r r r♥ ♥s♠ ♠♥♠ ss é♥értrs st s♣érr à

♠rq té♦r strtr P♦ss♦♥ ♦rt♠q ♦♥strt t♦t

♦♥ ♣tr été t ♣♦r s srs rs ①♠♣ s♣

s ♠♦♥♦♣ôs r ♥♦s ♠♦♥tr q ♣t ss s é♥r ♣♦r rt♥s

srs ♥♦♥ rs

Page 52: Structures de Poisson logarithmiques: invariants
Page 53: Structures de Poisson logarithmiques: invariants

♣tr

♦♦♠♦♦ P♦ss♦♥

♦rt♠q

♦♠♠r ♦♥strt♦♥ érq ♦♦♠♦♦ P♦ss♦♥ ♦

rt♠q

èrs ♥rt ♦rt♠qs

trtr èr ♥rt sr ΩA(log I) ♥t ♣r♥ strtr P♦ss♦♥ ♦rt♠q ♣r♥♣ ♦♥ I.

♦♥strt♦♥ é♦♠étrq ♦♦♠♦♦ P♦ss♦♥

♦rt♠q

qs strtrs èr ss♦és ① strtrs

P♦ss♦♥ ♦rt♠qs

trtrs èr ♥rt sr ΩX(logD)

①♠♣s s r♦♣s ♦♦♠♦♦s P♦ss♦♥

♦rt♠qs

r♦♣ ♦♦♠♦♦ P♦ss♦♥ ♦rt♠qs s str

trs ♦s②♠♣tqs

♦♦♠♦♦ P♦ss♦♥ t P♦ss♦♥ ♦

rt♠q strtr P♦ss♦♥ x, y = 0, x, z =

0, y, z = xyz sr A = C[x, y, z]

♥tr♦t♦♥

♦s ♠♦♥trr♦♥s ♥s tt ♣rt q t♦t strtr P♦ss♦♥ ♦rt

♠q ♣r♥♣ ♥t sr ♠♦ s ér♥ts ♦r♠s ♦rt♠qs

♥ strtr èr ♥rt tt strtr é♦ ♥ r♣rés♥

tt♦♥ ♠♦ s ér♥ts ♦r♠s ♦rt♠qs ♣r s ért♦♥s

♦rt♠qs tt r♣rés♥tt♦♥ ♥t ♦♠♣① P♦ss♦♥ ♦rt♠q

♦s ♦♥s qqs r♦♣s ♦♦♠♦♦ ♦♠♣① ♦s ♠♦♥tr♦♥s q

s r♦♣s ♦♦♠♦♦ P♦ss♦♥ t P♦ss♦♥ ♦rt♠qs s strtrs

P♦ss♦♥ ♦s②♠♣tq s♦♥t s♦♠♦r♣s

Page 54: Structures de Poisson logarithmiques: invariants

♣tr ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

♦♥strt♦♥ érq ♦♦♠♦♦ P♦s

s♦♥ ♦rt♠q

♥s tt ♣rt A és♥r ♥ èr sr ♥ ♥♥ ♦♠♠tt ♥tr

R rtérstq ③ér♦ t I ♥ é ♣r♦♣r A.

èrs ♥rt ♦rt♠qs

♦s ♣♣r♦♥s ♥♥ t♦t ♥♥ éq♣é ♥ r♦t

♦t L ♥ ♥♥ q st ♥ ♣s ♥ A♠♦ ♥ é♥t♦♥ s♥t

é♥t♦♥ ❬♥rt ❪ ♥ ♣♣ strtr èr ♥rt

♥s L t♦t ♦♠♦♠♦r♣s♠ A♠♦s t èrs ρ : L → DerAs♦♠s à ♦♥t♦♥ ♦♠♣tté s♥t

[α, aµ] = ρ(α)(a)µ+ a[α, µ]

♥s st ♥♦s ♣♣r♦♥s èr ♥rt t♦t tr♣t (L, [−,−], ρ)

♦r♠é ♥ ♥♥ (L, [−,−]) q ♥ ♣s st ♥ A♠♦ t ♥ strtr

èr ♥rt ρ sr L.

Pr s♦ rté t♦t èr ♥rt (L, [−,−], ρ) sr r♣rés♥té ♣r

L. P♦r t♦s µ ∈ L t a ∈ A, ρ(µ)(a) sr ♥♦té s♠♣♠♥t µ(a).

♦♥t P,Q ① A♠♦s ①st ① ç♦♥s ♠ttr ♥ strtr

A♠♦ sr r♦♣ t HomR(A,B) à s♦r

r : A×HomR(P,Q) → HomR(P,Q), ra()(p) := r(a,)(p) := (a+)(p) = (ap)

t

l : A×HomR(P,Q) → HomR(P,Q), la()(p) := (a,)(p) := (a)(p) = a(p)

P♦r t♦t a ∈ A t ∈ HomR(P,Q), ♦♥ ♣♦s

δa := ra()− la().

Pr ♦♥strt♦♥ δa st ♥ ♥♦♠♦r♣s♠ R♥ér HomR(P,Q). ♦♥ ♣♦r

t♦t a, b ∈ A ♦♠♣♦sé δa δb st ♥ é♥

st rss ♥s ❬rss ❪ t ❱♥♦r♦ ♥s

❬❱♥♦r♦ ❪ ♦♥ ♦♣t é♥t♦♥ s♥t

é♥t♦♥ : P → Q st ♣♣é ♦♣értr ér♥t sr A ♦rr ♥érr

♦ é à s s st t t s ♣♦r t♦s a0, ..., as ∈ A ♦♥

δa0 δa1 ... δas() = 0

Page 55: Structures de Poisson logarithmiques: invariants

♦♥strt♦♥ érq ♦♦♠♦♦ P♦ss♦♥

♦rt♠q

♥ r♠rq q ♥s♠ s ♦♣értrs ér♥ts sr A ♦rr ≦ s ♦r♠ ♥

r♦♣ t s t♦♥s é♥s ♣r s rt♦♥s t ♦♥ ♥ t

① ♠♦s sr A à s♦r

s(P,Q) ♣♦r t♦♥ r t +s (P,Q) ♣♦r l. ♥ ♥♦t (+)s (P,Q) ♠♦

♦t♥ ♥ ♦♥♥t s ① t♦♥s

Pr s♦ s♠♣té +1 (P ) és♥r +1 (P, P ) ♣♦r t♦t A♠♦ P.

♥ s strt♦♥ ♣♦r t♦t ∈ s(P,Q), ♦♥

• P♦r s = 0 :

0 = δa()(p) = (ap)− a(p)

♣♦r t♦s a ∈ A t p ∈ P. ♦♥ s ♦♣értrs ér♥ts ♦rr ③ér♦ s♦♥t

①t♠♥t s ♣♣t♦♥s ♥érs P rs Q.

• P♦r s = 1 :

0 = (δab())(p) = δa((bp)− b(p)) = (abp)− b(ap)−a(bp)+ab(p).

tr♠♥t t s éé♠♥ts 1(P,Q) ér♥t rt♦♥

(abp)− b(ap)− a(bp) + ab(p) = 0.

♥s s ♦♣értrs ér♥ts ♦rr ≦ 1 A rs Q s♦♥t rtérsés

♣r rt♦♥

(ab)− b(a)− a(b) + ab(1) = 0

♣♦r t♦t a, b ∈ A. st ♣r♥r p = 1 ♥s ♣♣♦♥s ss

q♥ ért♦♥ A à rs ♥s Q st ♥ éé♠♥t HomR(A, Q)

ér♥t

(ab) = a(b) + b(a)

♣♦r t♦t a, b ∈ A. ♥ ♥♦t Der(A, Q) ♥s♠ s ts ért♦♥s P♦r

t♦t ∈ Der(A, Q), ♦♥

(δab())(1) = (ab)−b(a)−a(b)+ab(1) = (ab)−b(a)−a(b) = 0

♣♦r t♦t a, b ∈ A. ♦♥ Der(A, Q) st ♥ s♦s ♠♦ strt 1(A, Q).

été ♥trs s ① ♠♦s ②♥t ♦rsq (1) = 0 ♣♦r t♦t

∈ 1(A, Q).

♦t P ♥ Aèr t L ♥ P ♠♦ éq♣é ♥ strtr é♥

♣r ♥ r♦t [−,−].

é♥t♦♥ ♥ ♣♣ strtr P èr ♥rt sr L t♦t ♦♠♦

♠♦r♣s♠ A♠♦s ρ : L → 1(P, P ) stss♥t ♣r♦♣rété ♦♠♣t

té s♥t

[α, pµ] = ρ(α)(p)µ+ p[α, µ]

♣♦r t♦t α, µ ∈ L t p ∈ P.

Page 56: Structures de Poisson logarithmiques: invariants

♣tr ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

♦♠♠ ♥s s s èrs ♥rt ♥ P èr ♥rt

st ♥ qr♣t (L, [−,−], ρ, P ) ♦ù ρ st ♥ strtr P èr

♥rt sr L. ♦rsq♥ ♦♥s♦♥ ♥st ♣♦ss t♦t P èr

♥rt (L, [−,−], ρ) sr ♥♦té s♠♣♠♥t L.

♥ ♣r♦♣♦st♦♥ s♥t

Pr♦♣♦st♦♥ ♦t èr ♥rt sr A st ♥ Aèr

♥rt

Pr é♦ t q DerA st ♥ s♦s ♠♦ 1(A,A).

♦s ♥ és♦♥s q s èrs ♥rt s♦♥t ♥ s ♣rtr P

èrs ♥rt Pr rs t♦t strtr P èr ♥rt

sr L ♥t s r♣rés♥tt♦♥ ♣r s ♦♣értrs ér♥ts ♦rr sr A. ♥

♣t ♦♥ é♥r ♥ ♦♦♠♦♦ ss♦é à tt r♥èr

♦t L ♥ P èr ♥rt t q ♥ ♥tr ♥tr

é♥t♦♥ ♥ ♣♣ P ♦♥ ♠♥s♦♥ q ♦ q−P ♦♥ ss♦é à

ρ t♦t ♣♣t♦♥ q♥ér tr♥é L rs P.

♥ ♥♦tr Ltq(L,P ) s♣ s q − P ♦♥s Pr é♥t♦♥ ♦♥

Lt0(L,P ) = P.

♥ é♥t ♥ ♣♣t♦♥ ♥ér dρ : Ltq(L,P ) → Ltq+1(L,P ) ♣r ♦r♠

(dρf)(x1, ..., xq+1)

=q+1∑i=1

(−1)i+1ρ(xi)f(x1, ..., xi, ..., xq+1)

+q+1∑i<j

(−1)i+j+1f([xi, xj ], x1, ..., xi, ..., , xj , ..., xq+1)

Pr♦♣♦st♦♥ ♣♣t♦♥ dρ ér

dρ dρ = 0

Pr ♦s ♣r♦♣♦s♦♥s ♥ é ♣r ♦s réér♦♥s tr à ♥♥①

♣♦r ♥ ♣r ♦♠♣èt t été

• P♦r q = 1, ♦♥ ♣♦s = dρf ♣♦r t♦t f ∈ P. ♦rs ♣♦r t♦t x ∈ L ♦♥

(x) = ρ(x)f.

Pr rs

(dρg)(x1, x2) = ρ(x1)g(x2)− ρ(x2)g(x1)− g([x1, x2]).

♥ r♠♣ç♥t g ♣r , ♦♥ ♦t♥t

dρ dρ(f)(x1, x2) = ρ(x1)(x2)− ρ(x2)(x1)−([x1, x2])

= ρ(x1)ρ(x2)f − ρ(x2)ρ(x1)f − ρ([x1, x2])f

= ([ρ(x1), ρ(x2)]− ρ([x1, x2])) f

= 0

Page 57: Structures de Poisson logarithmiques: invariants

♦♥strt♦♥ érq ♦♦♠♦♦ P♦ss♦♥

♦rt♠q

• P♦r q = 3, ♦♥ ♣♦s

g(x1, x2) = (dρf)(x1, x2) = ρ(x1)f(x2)− ρ(x2)f(x1)− f([x1, x2]).

P♦r t♦t f ∈ Lt1(L,P ).Pr rs ♣♦r t♦s x1, x2, x3 ∈ L, ♦♥

(dρg)(x1, x2, x3) = ρ(x1)g(x2, x3)− ρ(x2)g(x1, x3) + ρ(x3)g(x1, x2)

−g([x1, x2], x3) + g([x1, x3], x2)− g([x2, x3], x1).

♥ r♠♣ç♥t g ♣r s♦♥ ①♣rss♦♥ ♦♥ ♦t♥t

(dρg)(x1, x2, x3)

= ρ(x1) (ρ(x2)f(x3)− ρ(x3)f(x2)− f([x2, x3]))

−ρ(x2) (ρ(x1)f(x3)− ρ(x3)f(x1)− f([x1, x3]))

+ρ(x3) (ρ(x1)f(x2)− ρ(x2)f(x1)− f([x1, x2]))

−ρ([x1, x2])f(x3) + ρ(x3)f([x1, x2]) + f([[x1, x2], x3])

+ρ([x1, x3])f(x2)− ρ(x2)f([x1, x3])− f([[x1, x3], x2])

−ρ([x2, x3])f(x1) + ρ(x1)f([x2, x3]) + f([[x2;x3], x1])

♥ t♦rs♥t s trs f(x3), f(x2) t f(x1) rs♣t♠♥t ♦♥ ♦t♥t

(dρg)(x1, x2, x3)

= (ρ(x1)ρ(x2)− ρ(x2)ρ(x1)− ρ([x1, x2])) f(x3)

+ (−ρ(x1)ρ(x3) + ρ(x3)ρ(x1) + ρ([x1, x3])) f(x2)

+ (ρ(x2)ρ(x3)− ρ(x3)ρ(x2)− ρ([x2, x3])) f(x1)

+f ([[x1, x2], x3]− [[x1, x3], x2] + [[x2;x3], x1])

+ρ(x1)(f([x2, x3])− f([x2, x3])) + ρ(x2)(f([x1, x3])

−f([x1, x3])) + ρ(x3)(f([x1, x2])− f([x1, x2]))

été ré é♦ ♥tté ♦ r♦t [−,−] t t

q ρ ♦♠♠t s r♦ts

é♥t♦♥ ♦♦♠♦♦ ♦♠♣①

... // Lt∗+1(L,P ) // Lt∗(L,P ) // ...

st ♣♣é ♦♦♠♦♦ ♥rt L à rs ♥s P.

♥ s sss s ♣s ♠♣♦rt♥t èrs ♥rt (L, ρ) st

♣♦r q ρ : L → DerA st ♥ ♠♦♥♦♠♦r♣s♠ èrs ♦♥

r♠rqr q♥ é♥ér ♥ s♦s ♥s♠ L DerA ♠♥ ♥s♦♥ st ♥

èr ♥rt s t s♠♥t s st ♥ s♦s ♠♦ DerA.

♥s DerA(log I) t DerA s♦♥t s èrs ♥rt ♦♦♠♦♦

♥rt DerA(log I) rs♣ DerA st ♦♦♠♦♦ ♠

♦rt♠q A.

♥s st I és♥ ♥ é A ♥♥ré ♣r S = u1, ..., up ⊂ A.♦t (L, ρ) ♥ èr ♥rt sr A. ♥ ♠♠ s♥t

Page 58: Structures de Poisson logarithmiques: invariants

♣tr ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

♠♠ ρ(L)∩DerA(log I) st ♥ s♦s èr ♥♦♥ tr DerA.

Pr ρ ét♥t ♥ ♦♠♦♠♦r♣s♠ èrs ρ(L)∩DerA(log I) st r♠é

♣♦r r♦t DerA. Pr rs ♣♦r t♦t l ∈ L, u ∈ S uρ(l) = ρ(ul) ∈ρ(L) ∩DerA(log I).

é♥t♦♥ ❯♥ èr ♥rt ♦rt♠q ♦♥ I st ♥ tr♣t

(L, [−,−], ρ, I) ♦r♠é ♥ A♠♦ L éq♣é ♥ r♦t [−,−] t ♥

♦♠♦♠♦r♣s♠ èr ρ : L→ DerA(log I) stss♥t

♦t (L, [−,−], ρ, I) ♥ èr ♥rt ♦rt♠q ♦♥ I P♦rt♦t x, y, z ∈ L, a ∈ A, ♦♥

(ρ[x, y]− [ρ(x), ρ(y)])(a).z

= ρ[x, y](a).z − [ρ(x), ρ(y)](a).z

= ρ[x, y](a).z − ρ(x)[ρ(y)(a)].z + ρ(y)[ρ(x)(a)].z

= [[x, y], az]− a[[x, y], z]− [x, ρ(y)(a).z] + ρ(y)(a)[x, z] + [y, ρ(x)(a)z]− ρ(x)(a)[y, z]

= [[x, y], az]− a[[x, y], z]− [x, [y, az]] + [x, a[y, z]]+

+[y, a[x, z]]− a[y, [x, z]] + [y, [x, az]]− [y, a[x, z]]− [x, a[y, z]] + a[x, [y, z]]

= − ([az, [x, y]] + [x, [y, az]] + [y, [x, az]])− a ([[x, y], z] + [[y, z], x] + [[z, x], y])

= 0.

♥s (ρ[x, y] − [ρ(x), ρ(y)])(a) = 0 ♣♦r t♦t a ∈ A s A st s♥s t♦rs♦♥ ♦♥

ρ[x, y] = [ρ(x), ρ(y)]. st ♣r ♣r♦♣♦st♦♥ s♥t

Pr♦♣♦st♦♥ ♦t L ♥ A♠♦ s♥s t♦rs♦♥ Ann(L) = 0

❯♥ ♦♠♦♠♦r♣s♠ ρ : L → DerA(log I) A♠♦s st ♥ strtr èr

♥rt ♦rt♠q s t s♠♥t s stst

♦t P ♥ A♠♦ ♥ ♣♦s DerA(log I, P ) = δ ∈ DerA(A, P )t q δ(u) ∈uP ; ♣♦r t♦tu ∈ S. ♥ é♥t♦♥ s♥t

é♥t♦♥ DerA(log I, P ) st ♣♣é ♠♦ s ért♦♥s A ♦rt

♠qs ♣r♥♣s ♦♥ I à rs ♥s P.

s♥st q DerA(log I) = DerA(log I,A).

♦t ∈ +1 (P ); ♣♦r t♦t a, b ∈ A, p ∈ P, ♦♥

(r(a+ b)− l(a+ b))p = (ap)− a(p) +(bp)− b(p)

s♥ st q ♥t ♥ ♠♦r♣s♠ r♦♣s σ : A → HomR(P,Q) a 7→δa = r(a)− l(a).

Pr♦♣♦st♦♥ P♦r t♦t ∈ +1 (P ) t t♦t A♠♦ Q,

σ ∈ Der(A,HomR(P,Q)).

Pr Psq ∈ +1 (P ), ♣♦r t♦s a, b ∈ A, p ∈ P ♦♥

(abp) = b(ap) + a(bp)− ab(p).

Page 59: Structures de Poisson logarithmiques: invariants

♦♥strt♦♥ érq ♦♦♠♦♦ P♦ss♦♥

♦rt♠q

♦♥

(abp)− ab(p) = (bσ(a) + aσ(b))(p).

stàr

σ(ab) = aσ(b) + bσ(a)

♦ù réstt

♥s♦♥ s ért♦♥s ♦rt♠qs ♦♥ I ♥s DerA ♣r♠t ♥

sr s ♦♣értrs ér♥ts ts q σ ∈ DerA(log I).P♦s♦♥s

+1 (log I) = ∈ +1 (P )|σ ∈ DerA(log I).

+1 (log I) st ♥♦♥ tr r ♣♦r t♦t ∈ +1 (P ), u ∈ S, ♦♥ u ∈+1 (log I). Pr rs +1 (log I) ♣♦ssè ♣r♦♣rété s♥t

Pr♦♣♦st♦♥ +1 (log I) st ♥ èr ♥rt ♦rt♠q

♦♥ I.

Pr ♣rès q ♣réè ①st ♥ ♣♣t♦♥

σ : +1 (log I) → DerA(log I) 7→ σ

P♦r t♦t f ∈ A, s ∈ P ♦♥ σf = fσ t

σ[ϕ1,ϕ2](f)s = [ϕ1, ϕ2](fs)− f [ϕ1, ϕ2](s)

= ϕ1ϕ2(fs)− ϕ2ϕ1(fs)− fϕ1ϕ2(s) + ϕ2ϕ2(s)

= ϕ1(σϕ2(f)s+ fϕ2(s))− ϕ2(σϕ1(f)s+ fϕ1(s))− f [ϕ1, ϕ2]s

= ϕ1(σϕ2(f)s) + ϕ1(fϕ2(s))− ϕ2(σϕ1(f)s)− ϕ2(fϕ1(s))− f [ϕ1, ϕ2]s

= σϕ1(σϕ2(f))s+ σϕ2(f)ϕ1(s) + σϕ1(f)ϕ2(s) + fϕ1(ϕ2(s))−σϕ2(σϕ1(f))s− σϕ1(f)ϕ2(s)− σϕ2(f)ϕ1(s)− fϕ2(ϕ1(s))− f [ϕ1, ϕ2]s

= [σϕ1 , σϕ2 ](f)s

tr ♣rt ϕ1, ϕ2 ∈ +1 (log I), f ∈ A t s ∈ P ♥♦s ♦♥s

[ϕ1, fϕ2] = ϕ1(fϕ2(s))− (fϕ2)(ϕ1(s))

= fϕ1(ϕ2(s)) + σϕ1(f)(ϕ2(s))− fϕ2(ϕ1(s))

= σϕ1(f)(ϕ2(s)) + f [ϕ1, ϕ2]

♥ ♣♦s

+1 (log I, P ) := ∈ +1 (A, P );σ ∈ DerA(log I, P ). ♦rs +1 (log I, P )st rtérsé ♣r

é♦rè♠ P♦r t♦t ∈ HomR(A, P ) s ♣r♦♣rétés s♥ts s♦♥t éq

♥ts

∈ +1 (log I, P )

σ ∈ Der(log I,HomR(A, P ))

Page 60: Structures de Poisson logarithmiques: invariants

♣tr ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

Pr ♦♥t a, b ∈ A t ∈ HomR(A, P ).

σ(u) ∈ uHomR(A, P )t

σ(ab) = aσ(b) + bσ(a)

♦rs ♣♦r t♦t p ∈ P,

(abp) = a(bp) + b(ap)− ab(p)

Pr rs

δa,b(p) = (abp)− a(bp)− b(ap) + ab(p)

q ♠♣q ♣rès éqt♦♥ q δa,b = 0. ♦♥ st ♥ ♦♣értr

ér♥t ♦rr ≤ 1.

ré♣r♦q é♦ é♥t♦♥ +1 (log I, P ).

♥ ♥♦t

DI(B ⊂ P ) := ∈ DerA(log I, P )|(A) ⊂ BPr é♥t♦♥ DI(B ⊂ P ) = DerA(log I, B) s B st ♥ s♦s ♠♦ P.

♥ é♥t ♣r ♥t♦♥ ♥ st DIi (P ) ⊂ +

1 (log I, P ), i ≧ 0 A♠♦s

♥ ♣♦s♥t DI0 (P ) = P,DI

1 (P ) = DerA(log I, P ) t DIi+1(P ) = DI(DI

i (P ) ⊂((+

1 )i(log I, P ))) ♦ù (+

1 )i(P ) = +

1 (...(+1 (log I, P )...).

é♥t♦♥ s éé♠♥ts DIi (P ) s♦♥t ♣♣és ♣♦②ért♦♥s A ♥s P

♦rt♠qs ♦♥ I. ♣r♦♣♦st♦♥ s♥t ♦♥♥ ♥ sr♣t♦♥ été DI

i (P )

Pr♦♣♦st♦♥ P♦r t♦t i ≧ 1 ♥ éé♠♥t ∈ HomK(A, DIi−1) ♣♣rt♥t à

DIi s t s♠♥t s ♣♦r t♦t a, b ∈ A, stst s ♣r♦♣rétés s♥ts

(ab) = a(b) + b(a)

(a, b) +(b, a) = 0

Pr st ♥tq à ♣r♦♣♦sé ♥s ❬rss ❪

rss♦rt ♠♠ q DIi (A) t Hom(

i∧Ω(log I,A)) s♦♥t s♦♠♦r♣s

trtr èr ♥rt sr ΩA(log I) ♥t ♣r♥ strtr P♦ss♦♥ ♦rt♠q ♣r♥♣ ♦♥ I.

♥s tt ♣rt ♥♦s ♦♣t♦♥s s ♥♦tt♦♥s st♦♥ ♥ s♣♣♦sr

♥ ♦tr q A st éq♣é ♥ strtr P♦ss♦♥ ♦rt♠q ♣r♥♣

♦♥ ♥ é I ♥♥ré ♣r S t ♥♦s és♥r♦♥s ♦r♠ ss♦é ♣r ω.

ér♥t d sr s♠♣♠♥t ♥♦té d t ♦♠♣① ss♦é

0d // A d // 1∧

ΩA(log I)d // ... d // i∧

ΩA(log I)d // i∧

ΩA(log I)d // ...

sr ♣♣é ♦♠♣① ♠ ♦rt♠q A.

Page 61: Structures de Poisson logarithmiques: invariants

♦♥strt♦♥ érq ♦♦♠♦♦ P♦ss♦♥

♦rt♠q

trtr ♥t sr ΩA(log I)

♣r♦♣♦st♦♥ s♥t ♦♠♣èt s ♣r♦♣rétés éré s ér

t♦♥s ♦rt♠qs

Pr♦♣♦st♦♥ ♦t δ ∈ DerR(log I). P♦r t♦tx

u∈ S−1ΩR(A), ♦♥

Lδ(x

u) =

1

uLδ(x)−

δ(u)

u

x

u

Pr ♥ t ♣♦r t♦t x ∈ ΩA, u ∈ I∗,Lδ(x) = Lδ(ux

u) = uLδ(

x

u) + δ(u)

x

u.

♦♥ Lδ(x

u) =

1

uLδ(x)−

δ(u)

u

x

u.

râ à tt ♣r♦♣♦st♦♥ ♥♦s ♦♥s s ♣r♦♣rétés s♥ts

♦r♦r P♦r t♦t u ∈ S t δ ∈ DerK(log I) ♦♥

Lδ(du

u) = d(

δ(u)

u)

Pr ♦tdu

u∈ ΩA(log I). ♦s és♦♥s Pr♦♣♦st♦♥ q

Lδ(d(u)

u) =

1

uLδ(d(u))−

δ(u)

u

d(u)

u

=1

ud(δ(u))− δ(u)

u

d(u)

u

Psq δ ∈ DerA(log I), ①st ♦♥ c ∈ A∗ t q δ(u) =

uc. s♥st qdδ(u)

u= d(c) +

d(u)

u= d(

δ(u)

u) +

δ(u)

u

d(u)

ut ♦♥

Lδ(d(u)

u) = d(

δ(u)

u) +

δ(u)

u

d(u)

u− δ(u)

u

d(u)

u= d(

δ(u)

u)

♦r♦r P♦r t♦t strtr P♦ss♦♥ ♦rt♠q ♣r♥♣ ♦♥

I sr A ♣♣t♦♥ ♠t♦♥♥♥ ♦rt♠q ss♦é H ♦♥

LH(d(u)

u)

(d(v)

v) = d

(1

uvu, v

)

♣♦r t♦t u, v ∈ S.

Pr ♦♥t u, v ∈ S. ♣rès é♥t♦♥ H, ♦♥

H(d(u)

u) =

1

uH d(u) = 1

uu,− =: ϕ

♥ ♣♣q♥t ♣r♦♣♦st♦♥ ♦♥ ♦t♥t

LH(d(u)

u)

(d(v)

v

)= Lϕ

d(v)

v

= d

(ϕ(v)

v

)

= d

(1

uvu, v

)

Page 62: Structures de Poisson logarithmiques: invariants

♣tr ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

♣r♦♣♦st♦♥ s♥t ♦♥♥ s ①♣rss♦♥s éré s ér♥ts

♦r♠s ♦rt♠qs ♦r♠ qdu

u ♦♥ s ért♦♥s ♦rt♠qs

♣r♥♣s

Pr♦♣♦st♦♥ ♦t H ♣♣t♦♥ ♠t♦♥♥♥ ♦rt♠q ss♦é à

♥ strtr P♦ss♦♥ ♦rt♠q ♣r♥♣ ♦♥ I ♦r♠ ss♦é

ω. P♦r t♦t a ∈ A t u, v ∈ S, ♦♥

LH(a

d(u)

u)

(d(v)

v) = ad(

1

uvu, v) + 1

uvu, vd(a)

LH(a

d(u)

u)

(bd(v)

v) =

1

uu, bd(v)

v+

b

uvu, vd(a) + bad(

1

uvu, v)

LH(b

d(v)

v)

(ad(u)

u) =

b

vv, ad(u)

u+

a

uvv, ud(b) + abd(

1

uvv, u)

d

(ω(a

d(u)

u, bd(v)

v)

)= abd

(1

uvu, v

)+

b

uvu, vd(a) + a

uvu, vd(b)

Pr tt ♣r é♦ ♦r♦r ♦s r♥♦②♦♥s à ♥♥①

tt ♣r♦♣♦st♦♥ ♦♥ ét s réstts

♦r♦r ♦♥t a, b ∈ A t u, v ∈ S. ♥

−dω(aduu, bdv

v) + L

H(adu

u)

(bdv

v)− L

H(bdu

u)

(adv

v) =

=a

uu, bd(v)

v+b

va, vdu

u+ abd(

1

uvu, v

Pr ♦s és♦♥s ♣r♦♣♦st♦♥ t ♦r♦r q

−dω(aduu, bdv

v) + L

H(adu

u)

(bdv

v)− L

H(bdu

u)

(adv

v) =

= −abd[ 1uv

u, v]− b

uvu, vda− a

uvu, vdb+ a

uu, bdv

v+

b

uvu, vda+

+abd(1

uvu, v) + b

va, vdu

u+

a

uvu, vdb+ abd(

1

uvu, v).

♣rès s♠♣t♦♥ ♦♥ ♦t♥t

−dω(aduu, bdv

v) + L

H(adu

u)

(bdv

v)− L

H[bdu

u]

(adv

v)

=a

uu, bdv

v+b

va, vdu

u+ abd(

1

uvu, v

♦r♦r s♥t ♥♦s ♣r♠t rtr♦r ①♣rss♦♥ é♥ér r♦t

P♦ss♦♥ ♥t sr ΩA.

Page 63: Structures de Poisson logarithmiques: invariants

♦♥strt♦♥ érq ♦♦♠♦♦ P♦ss♦♥

♦rt♠q

♦r♦r ♦♥t a, b ∈ A t u, v ∈ S. ♥

−dω(adu, bdv)+LH(ad(u))(bdv)−LH(bdu)(adv) = au, bdv+ba, vdu+abd(u, v)

Pr tt été rést s ♣r♦♣rétés s♥ts

d[ω(adu, bdv)] = au, vdb+ bu, vda+ abd[u, v]. LH(adu)(bd(v)) = abd[u, v] + au, bdv + bu, vda LH(bdv)(ad(u)) = abd[v, u] + bv, adu+ av, udb

♥ ♥ ét é♠♥t q

♦r♦r ♦♥t a, b ∈ A t u, v ∈ S. ♥

−dω(aduu, bdv) + L

H(adu

u)

(bdv) − LH(bdu)(adv

v) =

a

uu, bd(v) + ba, vdu

u+

abd(1

uu, v

Pr

P♦r t♦t a, b ∈ A t u, v ∈ S ♦♥

d(ω(adu

u, bdv)) = d(

ab

uu, v)

= [1

uu, v]d(ab) + abd(

1

uu, v)

=a

uu, vdb+ b

uu, vd(a) + abd(

1

uu, v)

LH[a

du

u]

(bdv) = aLH[d(u)

u]

(bdv) + σ(H[du

u])(bdv)d(a)

= a(bLH(du

u)

(d(v)) + H(du

u)(b)dv) +

b

uu, vd(a)

= abd(1

uu, v) + a

uu, bd(v) + b

uu, vd(a)

LH[(bdv)](adu

u) = bLH(dv)(a

du

u) + σ(H(d)(v))(a

du

u)d(b)

= b(aLH(dv)(du

u) + H(dv)(a)

du

u) +

a

uv, ud(b)

= bad(1

uv, u) + bv, adu

u+a

uv, ud(b)

s♥st q

−dω(aduu, bd(v)) + L

H(adu

u)

(bdv)− LH(bdu)(adv

v)

=a

uu, bdv + ba, vd(u)

u+ abd

(1

uu, v

)

♦t S ♥ ♣rt ♠t♣t ♥ èr P♦ss♦♥ S. ♠♠ ss♦s

♠♦♥tr q ♦sé S−1A ért ♥♦♥q♠♥t ♥ strtr P♦ss♦♥ ♥t

♣r A

Page 64: Structures de Poisson logarithmiques: invariants

♣tr ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

♠♠ ♦t A ♥ èr P♦ss♦♥ P♦r t♦t ♣rt ♠t♣t

S ⊂ A, ♦sé S−1A ♣♦ssè ♥ strtr ♥♦♥q èr P♦ss♦♥

Pr és♥♦♥s ♣r −,− strtr P♦ss♦♥ sr A. ♦rs r♦t

a1s−11 , a2s

−12 = a1, a2(s1s2)−1 − a1, s2a2(s1s22)−1−

s1, a2a1(s21s2)−1 + a1a2s1, s2(s21s22)−1

st s♦♥ ♥q ♣r♦♦♥♠♥t sr S−1A.P♦s♦♥s

[α, β]ω = −dω(α, β) + LH(α)β − LH(β)α

♦rs [−,−]ω st R ♥ér ♥ts②♠étrq

s réstts ss♦s ①♣t♥t [−,−]ω sr s é♥értrs ΩA(log I).

♠♠ ♦t a, b ∈ A t u, v ∈ S

[adu

u, bdv

v

]

ω

=a

uu, bdv

v+b

va, vdu

u+ abd(

1

uvu, v)

[adu

u, bdv

]

ω

=a

uu, bdv + ba, vdu

u+ abd(

1

uu, v)

[adu, bdv]ω = au, bdv + ba, vdu+ abd(u, v)

[adu, b

dv

v

]

ω

= au, bduu

+b

va, vdu+ abd(

1

vu, v)

Pr s ♣r♦♣rétés s♦♥t ♥ ♦♥séq♥ rt Pr♦♣♦st♦♥ t

ss ♦r♦rs

P♦r q st ♣r♦♣rété ♦♥ ♣♦r t♦t a, b ∈ A t u, v ∈ S, ♦♥

d(ω(adu

u, bdv

v)) = abd(

1

uvu, v) + a

uvu, vdb+ b

uvu, vda

LH(a

du

u)

(bdv

v) =

a

uu, bdv

v+

b

uvu, vda+ abd(

1

uvu, v)

LH(b

dv

v)

(adu

u) =

b

vv, adu

u+

a

uvv, udb+ abd(

1

uvv, u)

t ♦♥

Page 65: Structures de Poisson logarithmiques: invariants

♦♥strt♦♥ érq ♦♦♠♦♦ P♦ss♦♥

♦rt♠q

−d(ω(aduu, bdv

v)) + L

H(adu

u)

(bdv

v)− L

H(bdv

v)

(adu

u)

= −abd( 1

uvu, v)− a

uvu, vdb− b

uvu, vda+ b

vv, adu

u

+a

uu, bdv

v+

b

uvu, vda+ abd(

1

uvu, v)− b

vv, adu

u

+ − a

uvv, udb− abd(

1

uvv, u)

=b

vv, adu

u+a

uu, bdv

v+ abd(

1

uvu, v)

+ [−abd( 1

uvu, v) + abd(

1

uvu, v)] + [− a

uvu, vdb− a

uvv, udb]

+[b

uvu, vda− b

uvu, vda]

=b

vv, adu

u+a

uu, bdv

v+ abd(

1

uvu, v)

♦ù [adu

u, bdv

v

]

ω

=a

uu, bdv

v+b

va, vdu

u+ abd(

1

uvu, v)

♠♥èr ♥♦ ♦♥ ♠♦♥tr s ♣r♦♣rétés t

♥ ♣rtr ♣♦r a = b = 1 ♦♥

♦r♦r P♦r t♦t u, v ∈ S, ♦♥

[du

u,dv

v

]

ω

= d(1

uvu, v)

[du,

dv

v

]

ω

= d(1

vu, v)

[du

u, dv

]

ω

= d(1

uu, v) [du, dv] = d(u, v).

Pr♦♣♦st♦♥ P♦r t♦t u, v, w ∈ S ♦♥ [[du

u,dv

v

]

ω

,dw

w

]

ω

+

[[dv

v,dw

w

]

ω

,du

u

]

ω

+

[[dw

w,du

u

]

ω

,dv

v

]

ω

= 0

Pr ❱♦r ♥♥①

♥s ♠ê♠ ♦t ♥♦s ♦♥s

Pr♦♣♦st♦♥ P♦r t♦t u, v ∈ S t w ∈ A ♦♥

[[du

u,dv

v

]

ω

, dw

]

ω

+

[[dv

v, dw

]

ω

,du

u

]

ω

+

[[dw,

du

u

]

ω

,dv

v

]

ω

= 0

[[du

u, dv

]

ω

, dw

]

ω

+

[[dv, dw]ω ,

du

u

]

ω

+

[[dw,

du

u

]

ω

, dv

]

ω

= 0

Pr ❱♦r ♥♥① ♣♦r ♣s ét

♦s ♦♥s à ♣rés♥t ♠♦♥trr q ♣♦r t♦s ω1 = a1du1u1

+ b1dv1, ω2 = a2du2u2

+

Page 66: Structures de Poisson logarithmiques: invariants

♣tr ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

b2dv2 t ω3 = a3du3u3

+ b3dv3 ♥s ΩA(log I) ♦♥

0 =

[[ω1, ω2]ω , ω3]ω + [[ω2, ω3]ω , ω1]ω + [[ω3, ω1]ω , ω2]ω

=

[[a1du1u1

, a2du2u2

]

ω

, a3du3u3

]

ω

+

[[a1du1u1

, a2du2u2

]

ω

, b3dv3

]

ω

+

[[a1du1u1

, b2dv2

]

ω

, a3du3u3

]

ω

+

[[a1du1u1

, b2dv2

]

ω

, b3dv3

]

ω

+

[[b1dv1, a2

du2u2

]

ω

, a3du3u3

]+

[[b1dv1, a2

du2u2

]

ω

, b3dv3

]

ω

+

[[b1dv1, b2dv2]ω , a3

du3u3

]+ [[b1dv1, b2dv2]ω , b3dv3]ω

+

[[a2du2u2

, a3du3u3

]

ω

, a1du1u1

]

ω

+

[[a2du2u2

, a3du3u3

]

ω

, b1dv1

]

ω

+

[[a2du2u2

, b3dv3

]

ω

, a1du1u1

]

ω

+

[[a2du2u2

, b3dv3

]

ω

, b1dv1

]

ω

+

[[b2dv2, a3

du3u3

]

ω

, a1du1u1

]+

[[b2dv2, a3

du3u3

]

ω

, b1dv1

]

ω

+

[[b2dv2, b3dv3]ω , a1

du1u1

]+ [[b2dv2, b3dv3]ω , b1dv1]ω

+

[[a3du3u3

, a1du1u1

]

ω

, a2du2u2

]

ω

+

[[a3du3u3

, a1du1u1

]

ω

, b2dv2

]

ω

+

[[a3du3u3

, b1dv1

]

ω

, a2du2u2

]

ω

+

[[a3du3u3

, b1dv1

]

ω

, b2dv2

]

ω

+

[[b3dv3, a1

du1u1

]

ω

, a2du2u2

]+

[[b3dv3, a1

du1u1

]

ω

, b2dv2

]

ω

+

[[b3dv3, b1dv1]ω , a2

du2u2

]+ [[b3dv3, b1dv1]ω , b2dv2]ω

r ♣rès ♠♠ ♦♥

[a1du1u1

, a2du2u2

]=a1u1

u1, a2du2u2

+a2u2

a1, u2du1u1

+ a1a2d

(1

u1, u2u1, u2

)

Page 67: Structures de Poisson logarithmiques: invariants

♦♥strt♦♥ érq ♦♦♠♦♦ P♦ss♦♥

♦rt♠q

t ♦♥[[a1du1u1

, a2du2u2

], a3

du3u3

]

=

[a1u1

u1, a2du2u2

, a3du3u3

]+

[a2u2

a1, u2du1u1

, a3du3u3

]+

[a1a2d

(1

u1, u2u1, u2

), a3

du3u3

]

[a1u1

u1, a2du2u2

, a3du3u3

]

=a1u1u2

u1, a2u2, a3du3u3

+a3u3

a1u1

u1, a2, u3du2u2

+a1a3u1

u1, a2d(

1

u2u3u2, u3

)

[a2u2

a1, u2du1u1

, a3du3u3

]

=a2u1u2

a1, u2u1, a3du3u3

+a3u3

a2u2

a1, u2, u3du1u1

+

a2a3u2

a1, u2d(

1

u3u1u1, u3

)

[a1a2d(

1

u1, u2u1, u2), a3

du3u3

]

=a3u3

a1a2, u3d(1

u1u2u1, u2) + a1a2

1

u1u2u1, u2, a3

du3u3

+a1a2a3d

(1

u3 1

u1u2u1, u2, u3

)

Pr rs ♣r♦♣♦st♦♥ s♥t ♦♥♥ qqs ♣r♦♣rétés rtérstqs

r♦t P♦ss♦♥ ♦rt♠q ♣r♥♣

Pr♦♣♦st♦♥ ♦♥t ui ∈ S, ai ∈ A−S i = 1, 2, 3 t −,− ♥ str

tr P♦ss♦♥ ♦rt♠q ♣r♥♣ ♦♥ I. ♥ s ♣r♦♣rétés s♥ts

P1

u3 1

u1u2u1, u2, u3+

1

u1 1

u2u3u2, u3, u1+

1

u2 1

u3u1u3, u1, u2 = 0

Pa1u1

a2u2

u2, a3, u1du3u3

=a1a2u1u2

u2, a3, u1du3u3

+

a1u1u2

a2, u1u2, a3du3u3

− a1a2u1u22

u2, a3u2, u1du3u3

Pa3u3

a1u1

u1, a2, u1du2u2

=a3a1u1u3

u1, a2, u3du2u2

+

a3u3u1

a1, u3u1, a2du2u2

− a3a1u3u21

u1, a2u1, u3du2u2

Pa3u3

a2u2

a1, u2, u3du1u1

=a3a2u3u2

a1, u2, u3du1u1

+

a3u3u2

a1, u2a2, u3du1u1

− a2a3u3u22

a1, u2u2, u3du1u1

Pa1u1

a3u3

a2, u3, u1du2u2

=a1a3u1u3

a2, u3, u1du2u2

+

a1u1u3

a2, u3a3, u1du2u2

− a1a3u1u23

a2, u3u3, u1du2u2

Page 68: Structures de Poisson logarithmiques: invariants

♣tr ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

Pa2u2

a3u3

u3, a1, u2du1u1

=a2a3u2u3

u3, a1, u2du1u1

+

a2u2u3

a3, u2u3, a1du1u1

− a2a3u2u23

u3, a1u3, u2du1u1

Pa2u2

a1u1

a3, u1, u2du3u3

=a2a1u2u1

a3, u1, u2du3u3

+

a2u2u1

a3, u1a1, u2du3u3

− a2a1u2u21

a3, u1u1, u2du3u3

P a3a11

u3u1u3, u1, a2

du2u2

=a3a1u3u1

, u3, u1a2du2u2

−a3a1u1u23

u3, u1u3, a2du2u2

− a3a1u3u21

u3, u1u1, a2du2u2

P a2a31

u2u3u2, u3, a1

du1u1

=a2a3u2u3

, u2, u3, a1du1u1

−a2a3u2u23

u2, u3u3, a1du1u1

− a2a3u3u22

u2, u3u2, a1du1u1

P a1a31

u1u2u1, u2, a3

du3u3

=a1a2u1u2

u1, u2, a3du3u3

−a1a2u1u22

u1, u2u2, a3du3u3

− a1a2u2u21

u1, u2u1, a3du3u3

Pr ❱♦r ♥♥①

s ♣r♦♣rétés ♦♥ ♦t♥t [[a1du1u1

, a2du2u2

], a3

du3u3

]+

[[a2du2u2

, a3du3u3

], a1

du1u1

]+

[[a3du3u3

, a1du1u1

], a2

du2u2

]=

a1u1u2

u1, a2u2, a3du3u3

+a3a1u3u1

u1, a2, u3du2u2

+a3u3u1

u1, a2a1, u3du2u2

+

− a3a1u21u3

u1, a2u1, u3du2u2

+a1a3u1

u1, a2d(1

u2u3u2, u3) +

a2u2u1

a1, u2u1, a3du3u3

+

+a3a2u3u2

a1, u2, u3du1u1

+a3u3u2

a1, u2a2, u3du1u1

− a3a2u3u22

a1, u2u2, u3du1u1

+

a2a3u2

a1, u2d(1

u1u3u1, u3) +

a1a2u1u2

u1, u2, a3du3u3

− a1a2u1u22

u1, u2u2, a3du3u3

+

− a1a2u21u2

u1, u2u1, a3du3u3

+a3a1u3

a2, u3d(1

u1u2u1, u2) +

a3a2u3

a1, u3d(1

u1u2u1, u2)

+a1a2a3d(1

u3 1

u1u2u1, u2, u3)+

a2u2u3

u2, a3u3, a1du1u1

+a1a2u1u2

u2, a3, u1du3u3

+a1u1u2

u2, a3a2, u1du3u3

+

− a1a2u22u1

u2, a3u2, u1du3u3

+a2a1u2

u2, a3d(1

u3u1u3, u1) +

a3u3u2

a2, u3u2, a1du1u1

+

+a1a3u1u3

a2, u3, u1du2u2

+a1u1u3

a2, u3a3, u1du2u2

− a1a3u1u23

a2, u3u3, u1du2u2

+

a3a1u3

a2, u3d(1

u2u1u2, u1) +

a2a3u2u3

u2, u3, a1du1u1

− a2a3u2u23

u2, u3u3, a1du1u1

+

− a2a3u22u3

u2, u3u2, a1du1u1

+a1a2u1

a3, u1d(1

u2u3u2, u3) +

a1a3u1

a2, u1d(1

u2u3u2, u3)

+a2a3a1d(1

u1 1

u2u3u2, u3, u1)+

Page 69: Structures de Poisson logarithmiques: invariants

♦♥strt♦♥ érq ♦♦♠♦♦ P♦ss♦♥

♦rt♠q

a3u3u1

u3, a1u1, a2du2u2

+a2a3u2u3

u3, a1, u2du1u1

+a2u2u3

u3, a1a3, u2du1u1

+

− a2a3u23u2

u3, a1u3, u2du1u1

+a3a2u3

u3, a1d(1

u1u2u1, u2) +

a1u1u3

a3, u1u3, a2du2u2

+

+a2a1u2u1

a3, u1, u2du3u3

+a2u2u1

a3, u1a1, u2du3u3

− a2a1u2u21

a3, u1u1, u2du3u3

+

a1a2u1

a3, u1d(1

u3u2u3, u2) +

a3a1u3u1

u3, u1, a2du2u2

− a3a1u3u21

u3, u1u1, a2du2u2

+

− a3a1u23u1

u3, u1u3, a2du2u2

+a2a3u2

a1, u2d(1

u3u1u3, u1) +

a2a1u2

a3, u2d(1

u3u1u3, u1)

+a3a1a2d(1

u2 1

u3u1u3, u1, u2)

tt r♥èr ①♣rss♦♥ ♥♦s és♦♥s q

Pr♦♣♦st♦♥ P♦r t♦s ai ∈ A t ui ∈ S i = 1, 2, 3, ♥

[[a1du1u1

, a2du2u2

], a3

du3u3

]+

[[a2du2u2

, a3du3u3

], a1

du1u1

]+

[[a3du3u3

, a1du1u1

], a2

du2u2

]= 0

Pr ❱♦r ♥♥①Pr rs ♥♦s ♦♥s s rt♦♥s s♥ts

[[a1

du1u1

, a2du2u2

]ω, b3dv3

]

ω

=a1u1u2

u1, a2u2, b3dv3 +b3a1u1

u1, a2, v3du2u2

+

b3u1

u1, a2a1, v3du2u2

− b3a1u21

u1, a2u1, v3du2u2

+a1b3u1

u1, a2d(1

u2u2, v3)+

a2u2u1

a1, u2u1, b3dv3 +b3a2u2

a1, u2, v3du1u1

+b3u2

a1, u2a2, , v3du1u1

+

−b3a2u22

a1, u2u2, v3du1u1

+a2b3u2

a1, u2d(1

u1u1, v3) +

a2a1u1u2

u1, u2, b3dv3+

− a1a2u21u2

u1, u2u1, b3dv3 −a1a2u1u22

u1, u2u2, b3dv3 + b3a1a2, v3d(1

u1u2u1, u2)

+b3a2a1, v3d(1

u1u2u1, u2) + a1a2b3d(

1

u1u2u1, u2, v3),

[[a2

du2u2

, b3dv3]ω, a1du1u1

]

ω

=a2u2

u2, b3v3, a1du1u1

+a1a2u1u2

u2, b3, u1dv3

+a1u1u2

u2, b3a2, u1dv3 −a1a2u1u22

u2, b3u2, u1dv3 +a1a2u2

u2, b3d(1

u1v3, u1)

+b3u2

a2, v3u2, a1du1u1

+a1b3u1

a2, v3, u1du2u2

+a1u1

a2, v3b3, u2du2u2

+a1b3a2, v3d(1

u1u2u2, u1) +

a2b3u2

u2, v3, a1du1u1

− a2b3u22

u2, a1u2, v3du1u1

+a1a2u1

b3, u1d(1

u2u2, v3) +

a1b3u1

a2, u1d(1

u2u2, v3)+

a2b3a1d(1

u1 1

u2u2, v3, u1)

Page 70: Structures de Poisson logarithmiques: invariants

♣tr ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

t

[[b3dv3, a1

du1u1

]ω, a2du2u2

]

ω

=b3u1

v3, a1u1, a2du2u2

+a2b3u2

v3, a1, u2du1u1

+a2u2

v3, a1b3, u2du1u1

+ b3a2v3, a1d(1

u1u2u1, u2) +

a1u1

b3, u1v3, a2du2u2

+a2a1u1u2

b3, u1, u2dv3 +a2u1u2

b3, u1a1, u2dv3 −a2a1u21u2

b3, u1u1, u2dv3+a1a2u1

b3, u1d(1

u2v3, u2) +

b3a1u1

v3, u1, a2du2u2

− b3a1u21

v3, u3u1, a2du2u2

+a1a2u2

b3, u2d(1

u1v3, u1) +

a2b3u2

a1, u2d(1

u1v3, u1)+

a1b3a2d(1

u2 1

u1v3, u1, u2)

.

râ ①qs ♥♦s ♦t♥♦♥s ♣r♦♣♦st♦♥ s♥t

Pr♦♣♦st♦♥ ♦♥t ai, v3 ∈ A t ui ∈ S i = 1, 2. ♥

[[a2

du2u2

, b3dv3]ω, a1du1u1

]

ω

+

[[a1

du1u1

, a2du2u2

]ω, b3dv3

]

ω

+

[[b3dv3, a1

du1u1

]ω, a2du2u2

]

ω

= 0

Pr ❱♦r ♥♥①

♠rq ♦♥t u1, u3 ∈ S t a1, a3, b2, v2 ∈ A ♥ [[a1

du1u1

, b2dv2, ]ω, a3du3u3

]

ω

=a1u1

u1, b2v2, a3du3u3

+a3a1u3u1

u1, b2, u3dv3 +

a3u3u1

a1, u3u1, b2dv3 − a3a1u3u21

u1, b2u1, u3dv2 +a1a3u1

u1, b2d(1

u3v2, u3) +

b2u1

a1, v2u1, a3du3u3

+a3b2u3

a1, v2, u3du1u1

+a3u3

b2, u3a1, v2du1u1

+

a3b2a1, v2d(1

u1u3u1, u3) +

a1b2u1

u1, v2, a3du3u3

− a1b2u21

u1, a3u1, v2du3u3

+

a3a1u3

b2, u3d(1

u1u1, v2) +

a3b2u3

a1, u3d(1

u1u1, v2) +

a1b2a3d(1

u3 1

u1u1, v2, u3),

[[b2dv2, a3

du3u3

]ω, a1du1u1

]

ω

=b2u3

v2, a3u3, a1du1u1

+a1b2u1

v2, a3, u1du3u3

+a1u1

v2, a3b2, u1du3u3

+ b2a1v2, a3d(1

u3u1u3, u1) +

a3u3

b2, u3v2, a1du1u1

+a1a3u3u1

b2, u3, u1dv2 +a1u3u1

b2, u3a3, u1dv2 −a1a3u23u1

b2, u3u3, u1dv2+a3a1u3

b3, u3d(1

u1v2, u1) +

b2a3u3

v2, u3, a1du1u1

− b2a3u23

v2, u3u3, a1du1u1

+a3a1u1

b2, u1d(1

u3v2, u3) +

a1b2u1

a3, u1d(1

u3v2, u3)+

a3b3a1d(1

u1 1

u3v2, u3, u1)

Page 71: Structures de Poisson logarithmiques: invariants

♦♥strt♦♥ érq ♦♦♠♦♦ P♦ss♦♥

♦rt♠q

t

[[a3

du3u3

, a1du1u1

]ω, b2dv2

]

ω

=a3u3u1

u3, a1u1, b2dv2 +b2a3u3

u3, a1, v2du1u1

+

b2u3

u3, a1a3, v2du1u1

− b2a3u23

u3, a1u3, v2du1u1

+a3b2u3

u3, a1d(1

u1u1, v2)+

a1u1u3

a3, u1u3, b2dv2 +b2a1u1

a3, u1, v2du3u3

+b2u1

a3, u1a1, v2du3u3

+

−b2a1u21

a3, u1u1, v2du3u3

+a1b2u1

a3, u1d(1

u3u3, v2) +

a1a3u3u1

u3, u1, b2dv2+

−a3a1u23u1

u3, u1u3, b2dv2 −a3a1u3u21

u3, u1u1, b2dv2 + b2a3a1, v2d(1

u3u1u3, u1)

+b2a1a3, v2d(1

u3u1u3, u1) + a3a1b2d(

1

u3u1u3, u1, v2).

tt r♠rq ♥♦s és♦♥s ♣r♦♣♦st♦♥ s♥t

Pr♦♣♦st♦♥ P♦r t♦t u1, u3 ∈ S t a1, a3, b2, v2 ∈ A ♦♥

[[a1

du1u1

, b2dv2, ]ω, a3du3u3

]

ω

+

[[b2dv2, a3

du3u3

]ω, a1du1u1

]

ω

+

[[a3

du3u3

, a1du1u1

]ω, b2dv2

]

ω

= 0

Pr é♦ ♥ s♠♣ ♣♣t♦♥ ♥tté ♦ t ♣r♦♣rété ♥ts②♠étr −,−. ♦♥tr♦♥s ♣r ①♠♣ q

a3a1b2d(1

u3u1u3, u1, v2)

+a3b3a1d(1

u1 1

u3v2, u3, u1) + a1b2a3d(

1

u3 1

u1u1, v2, u3)

= 0

♣♣♦♥s t♦t ♦r q

1

u3 1

u1u1, v2, u3 =

1

u3u1u1, v2, u3 −

1

u3u21u1, u3u1, v2

♣s

1

u1 1

u3v2, u3, u1 =

1

u1u3v2, u3, u1 −

1

u1u23v2, u3u3, u1

t ♣s

1

u3u1u3, u1, v2 =

1

u1u3u3, u1, v2 −

1

u1u23u3, u1u3, v2+

− 1

u3u21u1, v2u3, u1.

Page 72: Structures de Poisson logarithmiques: invariants

♣tr ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

s♥ st ♦♥ q

a1b2a3d(1

u3 1

u1u1, v2, u3) + a3a1b2d(

1

u3u1u3, u1, v2) + a3b3a1d(

1

u1 1

u3v2, u3, u1)

= a1b2a3d(1

u3 1

u1u1, v2, u3+ 1

u3u1u3, u1, v2+

1

u1 1

u3v2, u3, u1)

= a1b2a3d(1

u3u1u1, v2, u3 −

1

u3u21u1, u3u1, v2+

1

u1u3v2, u3, u1+

− 1

u1u23v2, u3u3, u1+

1

u1u3u3, u1, v2 −

1

u1u23u3, u1u3, v2 −

1

u3u21v2, u3u3, u1)

= a1b2a3d(1

u3u1(u1, v2, u3+ v2, u3, u1+ u3, u1, v2)+

−u1, v21

u3u21(u3, u1+ u1, u3)− u3, u1

1

u1u23(u3, v2+ v2, u3))

♥ ♦♥t râ à ♥tté ♦ r♦t −,− q

(u1, v2, u3+ v2, u3, u1+ u3, u1, v2) = 0

♦ù

−u1, v21

u3u21(u3, u1+ u1, u3)− u3, u1

1

u1u23(u3, v2+ v2, u3 = 0

♦♥t ♣r été ré

s éts ♣r s♦♥t ♦♥♥és ♥ ♥♥①

♦♥t u1 ∈ S t a1, b2, b3, v2, v3 ∈ A − S. ♣rès é♥t♦♥ [−,−]ω t s

♣r♦♣rétés −,−, ♥♦s ♦♥s

[[u1du1u1

, b2dv2]ω, b3dv3]ω =a1u1

u1, b2v2, b3dv3 +b3a1u1

u1, b2, v3dv2

+b3u1

a1, v3u1, b2dv2 −b3a1u21

u1, b2u1, v3dv2 +a1b3u1

u1, b2d(v2, v3)

+b2u1

a1, v2u1, b3dv3 + b3b2a1, v2, v3du1u1

+ b3b2, v3a1, v2du1u1

+b2b3a1, v2d(1

u1u1, v3) +

a1b2u1

u1, v2, b3dv3 −a1b2u21

u1, v2u1, b3dv3+

b3a1b2, v3d(1

u1u1, v2) + b3b2a1, v3d(

1

u1u1, v2) + a1b2b3d(

1

u1u1, v2, v3),

[[b2dv2, b3dv3]ω, u1du1u1

]ω = b2v2, b3v3, a1du1u1

+a1b2u1

v2, b3, u1dv3

+a1u1

b2, u1v2, b3dv3 + a1b2v2, b3d(1

u1v3, u1) + b3b2, v3v2, a1

du1u1

+a1b3u1

b2, v3, u1dv2 +a1u1

b3, u1b2, v3dv2 + a1b3b2, v3d(1

u1v2, u1)

+b1b3v2, v3, a1du1u1

+a1b2u1

b3, u1d(v2, v3) +a1b3u1

b2, u1d(v2, v3)

+a1b2b3d(1

u1v2, v3, u1)

Page 73: Structures de Poisson logarithmiques: invariants

♦♥strt♦♥ érq ♦♦♠♦♦ P♦ss♦♥

♦rt♠q

t

[[b3dv3, u1du1u1

]ω, b2dv2]ω =b3u1

v3, a1u1, b2dv2 + b2b3v3, a1, v2du1u1

+b2b3, v2v3, a1d(1

u1u1, v2) +

a1u1

b3, u1v3, b2dv2 +b2a1u1

b3, u1, v2dv3

+b2u1

a1, v2b3, u1dv3 −b2a1u21

u1, v2b3, u1dv3 +a1b2u1

b3, u1d(v3, v2)

+b3a1u1

v3, u1, b2dv2 −b3a1u21

u1, b2v3, u1dv2 + b3b2a1, v2d(1

u1v3, u1)+

+b2a1b3, v2d(1

u1v3, u1) + a1b2b3d(

1

u1v3, u1, v2)

♣rès rr♦♣♠♥t ♦♥ ♠♦♥tr à ♥tté ♦ r♦t P♦ss♦♥

−,− q

[[b3dv3, u1du1u1

]ω, b2dv2]ω + [[b2dv2, b3dv3]ω, u1du1u1

]ω + [[u1du1u1

, b2dv2]ω, b3dv3]ω = 0

♠ê♠ ♦♥ ♠♦♥tr q

♥ t♥t s ssttt♦♥s

a1 // a2 u1 // u2 b2 // b3 v2 // v3 b3 // b1 t

v3 // v1 ♦♥ ♦t♥t

[[b1dv1, u2du2u2

]ω, b3dv3]ω+[[b3dv3, b1dv1]ω, u2du2u2

]ω+[[u2du2u2

, b3dv3]ω, b1dv1]ω = 0

♥ t♥t s ssttt♦♥s a1 // a3 u1 // u3 b2 // b1

v2 // v1 b3 // b2 t v3 // v2 ♦♥ ♦t♥t

[[b2dv2, u3du3u3

]ω, b1dv1]ω+[[b1dv1, b2dv2]ω, u3du3u3

]ω+[[u3du3u3

, b1dv1]ω, b2dv2]ω = 0

è ♣r ♣r♦♣♦st♦♥ s♥t

Pr♦♣♦st♦♥ ♦♥t u1 ∈ S t a1, b2, b3, v2, v3 ∈ A−S. ♣rès é♥t♦♥

[−,−]ω t s ♣r♦♣rétés −,−, ♥♦s ♦♥s

[[b3dv3, u1du1u1

]ω, b2dv2]ω + [[b2dv2, b3dv3]ω, u1du1u1

]ω +

[[u1du1u1

, b2dv2]ω, b3dv3]ω = 0

[[b1dv1, u2du2u2

]ω, b3dv3]ω + [[b3dv3, b1dv1]ω, u2du2u2

]ω +

[[u2du2u2

, b3dv3]ω, b1dv1]ω = 0

[[b2dv2, u3du3u3

]ω, b1dv1]ω + [[b1dv1, b2dv2]ω, u3du3u3

]ω +

[[u3du3u3

, b1dv1]ω, b2dv2]ω = 0.

Page 74: Structures de Poisson logarithmiques: invariants

♣tr ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

é♦ s ♣r♦♣♦st♦♥s t ♥érté [−,−]ω,

q

é♦rè♠ ♦t (A, −,−) ♥ èr P♦ss♦♥ ♦rt♠q ♣r♥

♣ ♦♥ ♥ é I ♥♥ré ♣r S := u1, ..., up. r♦t [−,−]ω é♥ ♣r

♥t sr ΩA(log I) ♥ strtr èr

♦♥strt♦♥ ♥ r♣rés♥tt♦♥ ♣r s ért♦♥s ♦rt

♠qs ΩA(log I)

♦s s♦♥s q ♣♣t♦♥ ♠t♦♥♥♥ H : ΩA → DerA t♦t strtr

P♦ss♦♥ sr A st ♥ ♠♦r♣s♠ èrs stss♥t ♦♥t♦♥

♦♠♣tté r à s♦s st♦♥ ♥♦s ♠♦♥tr♦♥s q ♥s s s

strtrs P♦ss♦♥ ♦rt♠qs ♣r♥♣s ♦♥ I tt ♣♣t♦♥ s

♣r♦♦♥ ♥ ♥ ♣♣t♦♥ A♥ér H : ΩA(log I) → DerA(log I). ♦t x ①é

♥s ΩA(log I) ♣♣t♦♥ ρω(x) : A → A é♥ ♣r

ρω(x)(a) = ω(x, d(a)) st ♥ Rért♦♥ sr A.♥ t ♣♦r t♦t a ∈ A,ρω(x)(a) =

p∑i=1xiρω(

duiui

)(a) +n∑p+1

xiρω(dvi) =p∑i=1

xiuiui, a+

n∑p+1

xivi, a

♦♥ ρω(x) =p∑i=1

xiuiui,−+

n∑p+1

xivi,−. ♦♥ ρω(x) st ♥ ért♦♥ ♦rt

♠q ♦♠♠ s♦♠♠ s ért♦♥s ♦rt♠qs ♥s ①st ♥ ♦♠♦♠♦r

♣s♠ A♠♦ ρω : ΩA(log I) → DerA(log I) q à t♦t x ∈ ΩA(log I)ss♦ ρω(x).

♥ ρω = H.

♦♥t u ∈ I∗ t a, b ∈ A ts q adu

u∈ ΩA(log I). ♣rès q ♣réè

ω(adu

u, db) =

a

uu, b. ♦♥ ρω(a

du

u)(b) =

a

uu, b =

a

u(ad(u))(b) t ♦♥

ρω(adu

u) =

a

uu,−.

♥s

ρω[adu

u, bdv

v] = ρω

(a

uu, bdv

v+b

va, vdu

u+ abd(

1

uvu, v)

)

=a

uu, bρω(

dv

v) +

b

va, vρω(

du

u) + abρω(d(

1

uvu, v))

=a

uvu, bv,−+ b

vua, vu,−+ ab 1

uvu, v,−

=a

uvu, bv,−+ b

vua, vu,−+ ab

uvu, v,−+

− ab

u2vu, vu,− − ab

uv2u, vv,−

Pr rs ♦♥

Page 75: Structures de Poisson logarithmiques: invariants

♦♥strt♦♥ érq ♦♦♠♦♦ P♦ss♦♥

♦rt♠q

ρω(adu

u)

(ρω(b

dv

v)

)=

a

uu, b

vv,−

=a

uvu, bv,−+ ab

uu, 1

vv,−

=a

uvu, bv,−+ ab

uvu, v,− − ab

uv2u, vv,−,

ρω(bdv

v)

(ρω(a

du

u)

)=

b

vv, a

uu,−

=b

uvv, au,−+ ab

vv, 1

uu,−

=b

uvv, au,−+ ab

uvv, u,− − ab

vu2v, uu,−.

♦♥ [ρω(adu

u), ρω(b

dv

v)] =

a

uvu, bv,− +

ab

uvu, v,− − ab

uv2u, vv,− +

b

uvv, au,−− ab

uvv, u,−+ ab

vu2v, uu,−. r ♣rès ♥tté ♦

u, v,− − v, u,−+ −, u, v = 0.

♦♥ [ρω(adu

u), ρω(b

dv

v)] =

a

uvu, bv,− − ab

uv2u, vv,− − b

uvv, au,− +

ab

vu2v, uu,−+ ab

uvu, v,− − ab

uv2u, vv,−.

t ♦♥ ρω([adu

u, bdv

v]ω) = [ρω(a

du

u), ρω(b

dv

v)].

♠ê♠ ♦♥ é♠♦♥tr q ρω[adu

u, bdv] = [ρω(a

du

u), ρω(bdv)] t ρω[adu, bdv] =

[ρω(adu), ρω(bdv)]. ♥ ♦♥ ♣r♦♣♦st♦♥ s♥t

Pr♦♣♦st♦♥ ♦t (A; −′−) ♥ èr P♦ss♦♥ ♦rt♠q ♦♥

I. ♣♣t♦♥ A♥ér ρω : x 7→ ρω(x) st ♥ ♠♦r♣s♠ èrs

♠rq♦♥s ss q

[du

u, adv

v]ω =

1

uu, adv

v+ ad(

1

uvu, v)

=1

uu, adv

v+ a[

du

u,dv

v]

=

(1

uu,−

)(a)

dv

v+ a[

du

u,dv

v]

= ρω(du

u)(a)

dv

v+ a[

du

u,dv

v]

♣r♦♣♦st♦♥ s♥t é♥érs tt ♣r♦♣rété

Pr♦♣♦st♦♥ P♦r t♦s ωj ∈ ΩA(log I) t f ∈ A, ♦♥

[ωi, fωj ] = f [ωi, ωj ] + (ρω(ωi)(f))ωj .

Pr ❱♦r ♥♥①

♥ ♥s é♠♦♥tré é♦rè♠ s♥t

Page 76: Structures de Poisson logarithmiques: invariants

♣tr ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

é♦rè♠ ♦t strtr P♦ss♦♥ ♦rt♠q ♣r♥♣ ♦♥ ♥

é I ♥ Rèr A ♥t sr ΩA(log I) ♥ strtr ♥rt

tr♠♥t t ♣♦r t♦t strtr P♦ss♦♥ ♦rt♠q ♣r♥♣ ♦♥ ♥

é I, (ΩA(log I), ρω, [−,−]) st ♥ èr ♥rt

②♥t ♠♥ sr ΩA(log I), ♥ strtr ♥rt ♦♥ ♣t ♦ré♥♥t

♣♣qr t♥q Ps t ♥rt ♣♦r ♦♥strr ♥ ♦♠♣① ♥

q ♥♦s ♣r♠ttr ♦♥strr ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q P♦r

♣♦s♦♥s LaltA(ΩA(log I),M) ♥s♠ s ♣♣t♦♥s ♠t♥érs ♥t

s②♠étrqs sr ΩA(log I) à rs ♥s ♥ A♠♦ ♥rt M.

LaltA(ΩA(log I),M) st ♥ Rèr ré ♦♠♠tt ♣♦r ♦

sté♥ ♣r

α ∧ β(xi, ..., xp+q) =∑

σ

εσµ(α(xσ(1), ..., xσ(p))⊗ β(xσ(p+1), ..., xσ(p+q)))

♦ù µ : M ⊗M → M st ♥ ♠♦r♣s♠ ΩA(log I)♠♦s ♠♥ ér♥

t dρω rt♥②♥r ss♦é à r♣rés♥tt♦♥ ρω é♥ ♣r

dρω(f)(α0, ...αp) =p∑i=0

(−1)iρω(αi)f(α0, ...αi, ...αp)+∑i,j(−1)i+jf([αi, αj ], α0, ..., αi, ..., αj , ..., αp)

♦♥ ♦t♥t ♥ èr ér♥t ré ♦♥t ♦♦♠♦♦ ss♦é st

♥♦té H∗PS (A, −,−;M) . r H∗

PS (A, −,−;M) = Ext(U(A,ΩA(log I)))(A,M) s

ΩA(log I) ♦♠♠ A−♠♦ st ♣r♦t ♥ ♦♣t ♦♥ é♥t♦♥ s♥t

é♥t♦♥ H∗PS (A, −,−;M) st ♣♣é ♦♦♠♦♦ P♦ss♦♥ ♦rt

♠q à rs ♥s ♠♦ ♥rt M.

♣rès q ♣réè ♦r♠ ω ♥t ♣r tt strtr P♦ss♦♥ st ♥

éé♠♥t Lalt2A(ΩA(log I),A). ♥ s ♠♥ s ♥st ♣s ♥ ♦②

♦♠♣① Lalt∗A(ΩA(log I),A). ♣r♦♣♦st♦♥ s♥t ♣♣♦rt ♥ ré♣♦♥s à tt

♣ré♦♣t♦♥

Pr♦♣♦st♦♥ ♦r♠ ω st ♥ ♦② Lalt∗A(ΩA(log I),A).

Pr ❱♦r

♥ ♥♦tr [ω−,−] ss ♦♦♠♦♦ ω

é♥t♦♥ [ω−,−] st ♣♣é ss P♦ss♦♥ ♦rt♠q

(A, −,−; I).

♦♥strt♦♥ é♦♠étrq ♦♦♠♦♦

P♦ss♦♥ ♦rt♠q

♥ ♠♦♥tr ♥s ❬t♦ ❪ q ♣r (ΩX,p(logD), DerX,p(logD)) st ré①

P♦r t♦t δ ∈ DerX,p(logD) t α ∈ ΩX,p(logD) ♦♥ ♥♦t

(δ|α) = iδ(α).

Page 77: Structures de Poisson logarithmiques: invariants

♦♥strt♦♥ é♦♠étrq ♦♦♠♦♦ P♦ss♦♥

♦rt♠q

♦ù (−|−) és♥ r♦t té ♥tr ΩX,p(logD) t DerX,p(logD). ♦s

♦♥s ♠♦♥tré ♣tr q t♦ts s st♦♥s ΩX(logD) s♦♥t ♦r♠

gα =dh

h+ η

♦ù g st ♥ ♦♥t♦♥ ♦♦♠♦r♣ srD t q dimCD∩z ∈ U : g(z) = 0 ≤ n−2

r ♣rès s ♦♥strt♦♥s st♦♥ ♣♣t♦♥ ♠t♦♥♥♥ H ♥

s é♥t q ♣♦r s ♦r♠s ②♥t s ♣ôs ♥q♠♥t sr D. tr♠♥t t

s ♦♥strt♦♥s ♥ s♦♥t ts q ♣♦r ♥ ss ♣rés srs P♦r

ts srs ΩX,p(logD) ♦t êtr ♥♥ré ♣r s ♦r♠s r♠és s rtérs

tqs ♥ t sr s♦♥t ♦♥♥és ♣r é♦rè♠

♥s tt st♦♥ ♥♦s s♣♣♦sr♦♥s ♥ ♣s q D stst s ②♣♦tèss

é♦rè♠ t q ♦♥t♦♥ é♥t♦♥ h D st rrét Pr rs

♦♥ s♣♣♦s q X st éq♣é ♥ strtr P♦ss♦♥ −,− ♦rt♠q

♦♥ é ID é♥t♦♥ D. ♦♠♠ à st♦♥ ♥♦s és♥r♦♥s ♣r

H : ΩX → DerX ♣♣t♦♥ ♠t♦♥♥♥ ss♦é à tt strtr P♦ss♦♥

♦tr s♦ st ♣r♦♦♥r H sr ΩX(logD) Psq t♦ts s st♦♥s

ΩX(logD) ♣♥t s ♠ttr s♦s ♦r♠ ω = gdh

h+η

g g ∈ OX t η ∈ ΩX

♦rs ♣♦r t♦t δ ∈ DerX(logD), ω ∈ ΩX(logD) ♦♥

Lδgω = −1

g

δh

h

dh

h+

1

ghLδdh+

1

gLδη −

δ.g

H ét♥t ♣♣t♦♥ ♠t♦♥♥♥ ♥ strtr P♦ss♦♥ ♦♥

P♦r t♦t α1, α2, α3 ∈ ΩX

(H(α1)|α2) + (α1|H(α2)) = 0 (s♦tr♦♣)

(LHα1α2|Hα3)+ = 0

♥ ♣♦s

Hα := H(α0dh

h+ α1) =

α0

hH(dh) +H(α1.)

st ♣♣t♦♥ ♠t♦♥♥♥ ♦rt♠q ss♦é à strtr P♦ss♦♥

♦rt♠q ♣r♥♣ ♣♣t♦♥ ♠t♦♥♥♥ H. Pr rs

Lα0

hH(dh)+H(α1)

α =α0

hLH(dh)α−H(dh).α

dα0

h+α0

hH(dh)α

dh

h+ LH(α1)α

Page 78: Structures de Poisson logarithmiques: invariants

♣tr ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

♥ s ♠♥r s H ér s rt♦♥s s♠rs à P♦r ♦♥ r♠r

qr q ♣♦r t♦t αi =dh

h+ α1

i , i = 1, 2, 3 ♦♥

(LH(α1)

α2|H(α3))

=

(1

hLH(dh)α

12|1

hH(dh)

)−

(H(dh)(α1

2)

h

dh

h| 1hH(dh)

)+

(1

hLH(dh)α

12|H(α1

3)

)

−(H(dh)(α1

2)

h

dh

h|H(α1

3)

)−(H(α1

1)h

h

dh

h| 1hH(dh)

)−

(H((α1

1)

h

dh

h|H(α1

3)

)

+

(1

hLH(α1

1)dh|

1

hH(dh)

)

+

(1

hLH(α1

1)dh|H(α1

3)

)+

(LH(α1

1)α

12|1

hH(dh)

)+

(LH(α1

1)α

12|H(α1

3))

♥ ♣♦s

Gr(H) := H(α)⊕ α, α ∈ Ω1X(log ID)

s étés t ♥♦s ♣r♠tt♥t é♠♦♥trr té♦rè♠ s♥t ♦♥t

s éts ♣r s♦♥t r♥♦②és ♥ ♥♥①

é♦rè♠ ♦t H ♣♣t♦♥ ♠t♦♥♥♥ ♥ strtr P♦ss♦♥

♦rt♠q ♣r♥♣ ♣♣t♦♥ ♠t♦♥♥♥ H.

H : ΩX(logD) → DerX(logD) stst s ♣r♦♣rétés s♥ts

Gr(H) st s♦tr♦♣

P♦r t♦t αi, αj , αk ∈ ΩX(log ID) ♦♥ (LH(αi)

α2|H(α3))+ = 0

♥ ♥ ét ♦r♦r s♥t

♦r♦r P♦r t♦ts st♦♥s α1, α2 ΩX(logD), ♦♥

[Hα1, Hα2] = H(iHα1dα2 − iHα2

dα1 + d(Hα1, α2))

Pr ♦♥t α1, α2 ① st♦♥s ΩX(logD), ♣rès té♦rè♠ ♦♥

0

= −(LHα1α2|Hα3)+

= (HLHα1α2|α3)− (LHα2

α3, Hα1)− (LHα3α1|, Hα2)

= (HLHα1α2|α3)− (LHα2

α3, Hα1)− (iHα3dα1 + diHα3

α1|Hα2)

= (HLHα1α2|α3)− (LHα2

α3|Hα1)− dα1(Hα3|Hα2)− (diHα3α1|Hα2)

= (HLHα1α2|α3)− (LHα2

α3|Hα1) + dα1(Hα3|Hα2)− (diHα3α1|Hα2)

= (HLHα1α2|α3)− (LHα2

α3|Hα1) + (iHα2dα1|Hα3)− (diHα3

α1|Hα2)

= (HLHα1α2|α3)− (HiHα2

dα1, α3)− (diHα3α1|Hα2)− (LHα2

α3|Hα1)

= (HLHα1α2 − HiHα2

dα1|α3)− (diHα3α1|Hα2)− (LHα2

α3, Hα1)

= (HLHα1α2 − HiHα2

dα1|α3)− (diHα3α1|Hα2)− (iHα2

dα3 + diHα2α3|Hα1)

= (HLHα1α2 − HiHα2

dα1|α3)− (d(iHα3α1)|Hα2)− (iHα2

dα3|Hα1)− (diHα2α3|Hα1)

= (HLHα1α2 − HiHα2

dα1, α3)− Hα2(Hα3|α1)− Hα1(Hα2|α3)− dα3(Hα2, α1)

= (HLHα1α2 − HiHα2

dα1|α3)− Hα2(Hα3|α1)− Hα1(Hα2|α3) + (α3, [Hα2, Hα1])+

+Hα1(α3|Hα2)− Hα2(α3|Hα1)

= (HLHα1α2 − HiHα2

dα1 − [Hα2, Hα1]|α3)

Page 79: Structures de Poisson logarithmiques: invariants

♦♥strt♦♥ é♦♠étrq ♦♦♠♦♦ P♦ss♦♥

♦rt♠q

♦ù réstt

qs strtrs èr ss♦és ① strtrs P♦ss♦♥ ♦rt♠qs

P♦r t♦t m ∈ MD := OX [D] ♦♥ Hd log(m) ∈ DerX(logD).

MD és♥ s♦ss MX s s ♦♥t♦♥s ♠ér♦♠♦r♣s sr

X s ♦♥t♦♥s ♠ér♦♠♦r♣s ♣ôs sr D.

♦s r♣♣♦♥s q ♣♦r t♦t strtr P♦ss♦♥ ♦♦♠♦r♣ é♥ ♣r ♥

♣♣t♦♥ ♠t♦♥♥♥ H, s ♦♥t♦♥s ♠t♦♥♥♥s s♦♥t t♦ts ♦♦♠♦r♣s

sr X. ♥ ét rt♦♥ Hd log(m) ∈ DerX(logD) q rt♥s sss

♦♥t♦♥s ♠ér♦♠♦r♣s ♣♥t êtr ♠t♦♥♥♥s ♦rt♠qs st s s

♦♥t♦♥s ♠ér♦♠♦r♣s t②♣

m =

r∏

i=1

g

hrii

♦ù h =r∏i=1hi st ♦♥t♦♥ é♥t♦♥ D t g ♥ ♦♥t♦♥ s♥s ③ér♦s sr D.

♦s r♣♣♦♥s q t♦t strtr P♦ss♦♥ −,− s ♣r♦♦♥ ♠♥èr ♥q

♣r

u, abs =

1

bu, a − a

b2u, b

♥ ♥ ♥q strtr P♦ss♦♥ −,−s sr MX .

♥ st q ♣♦r t♦t m1,m2 ∈ MD s ①st♥t λ1, λ2 ∈ Z t a1, a2 ∈ O∗X ts q

mi =aihλi

tdmi

mi= ε(λi)λi

dh

h+daiai

♦ù ε(λi) és♥ s♥ λi.

♥ ♦♥sèr sr MD r♦t s♥t

m1,m2D =

(Hdm1

m1|dm2

m2) s mi ∈ MD −OX

(Hdm1|dm2

m2) s m2 ∈ MD −OX t m1 ∈ OX

(Hdm1|dm2) s mi ∈ OX

r♦t ♣♦ssè s ♣r♦♣rétés s♥ts

Pr♦♣♦st♦♥ r♦t −,−D ér s étés s♥ts

−,−D st C♥ér ♥ts②♠étrq

Page 80: Structures de Poisson logarithmiques: invariants

♣tr ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

m1,m2D =

1

m1m2m1,m2s s mi ∈ MD −OX

1

m2m1,m2s s m2 ∈ MD −OX t m1 ∈ OX

m1,m2 s mi ∈ OX

,

−,−D st ♥ ért♦♥ ♦rt♠q sr MD − OX ♥ ♥ ss

♦♠♣♦s♥ts

P♦r t♦s m1,m2 ∈ MD −OX ,1

m1m2m1,m2s ∈ OX .

Pr é♦ s ♣r♦♣rétés ♦r♠s ♦rt♠qs

♥ ♥ ét ♦r♦r s♥t

♦r♦r −,−D st ♥ strtr sr s MD ♣r♦♦♥♥t

−,−Pr t ♠♦♥trr q −,−D ér ♥tté ♦ sr s st♦♥s

rst♥ts MD. P♦r ♦♥ st♥r tr♦s s

s u, v ∈ MD −OX t a ∈ OX .

s v ∈ MD −OX t a, b ∈ OX .

s u, v, w ∈ MD −OX .

♥ s♣♣♦s u, v ∈ MD −OX t a ∈ OX ♦rs

u, v, aDD = u, 1vv, asD

=1

uvu, v, ass −

1

uv2u, vsv, as

s♥st ♦♥ q

u, v, aDD+ =

=1

uvu, v, ass −

1

uv2u, vsv, as+

1

uvv, a, uss −

1

u2va, usv, us+

1

uva, u, vss −

1

uv2u, vsa, vs

− 1

u2vu, vsa, us

ç♦♥ ♥♦ ♦♥ ♠♦♥tr s trs s s trs éts tt ♣r s♦♥t

♦♥♥és ♥ ♥♥①

♥ ♥ ér s ♣r♦♣rétés s♥ts s r♦ts −,−s t −,−DPr♦♣♦st♦♥ s r♦ts −,−s t −,−D ér♥t s ♣r♦♣rétés s

♥ts sr MX −OX

m1,m2D(m1,m2D,m3D + m2,m3D + m1,m3D)+ = 0

1

m1m2,m3sm2,m3s,m1s−

1

m2m3m2,m1s−

1

m3m1m3,m1s+ = 0

Page 81: Structures de Poisson logarithmiques: invariants

♦♥strt♦♥ é♦♠étrq ♦♦♠♦♦ P♦ss♦♥

♦rt♠q

trtrs èr ♥rt sr ΩX(logD)

Préé♠♠♥t ♥♦s ♦♥s ♠♦♥trr q t♦t strtr P♦ss♦♥ ♦rt♠q

♥t ♥ ♠♦r♣s♠ s① H : ΩX(logD) −→ DerX(logD). ♦s ♦♥s à

♣rés♥t ♠♦♥trr q ♠♦r♣s♠ st ♥ strtr ♥rt

P♦r t♦t α := α1dh

h+ αi1dxi, β = β1

dh

h+ βj1dxj .

♥ é♥t sr ΩX(logD) r♦t s♥t

[α, β]

=α1

hh, β1

dh

h+β1hα1, h

dh

h+α1

hh, βjdxj+

+βjα1, xjdh

h+ α1β

jd(1

hh, βj) + αixi, β1

dh

h+

+β1hαi, hdxi + αiβ1d(

1

hxi, h) + αixi, βjdxj + βjαi, xjdxi + αiβjdxi, xj,

t ♦♥ été s♥t

[α, aβ] =

a(α1

hh, β1

dh

h+β1hα1, h

dh

h+α1

hh, βjdxj + βjα1, xj

dh

h+

+α1βjd(

1

hh, xj) + αixi, β1

dh

h+β1hαi, hdxi

+β1αid(

1

hxi, h) + αixi, βjdxj + βjαi, xjdxi + αiβjdxi, xj)

+α1

hh, adh

h+α1β

j

hh, adxj

+αiβ1xi, adh

h+ αiβjxi, adxj

q ♣rès rr♦♣♠♥t ♥♦s ♦♥♥

[α, aβ] = H(α)(a)β + a[α, β]

♥s ♦♣tq ♠♥r ΩX(logD) ♥ strtr èr ♥rt ♠♦♥

tr♦♥s ♠♠ ss♥t s♥t

♠♠ r♦t [−,−] é♥t ♥s ΩX(logD) ♥ strtr èr

♥rt

Pr ♦♥t α1, α2, α3 ∈ ΩX(logD).

[[α1, α2], α3]

= [LHα1α2 − iHα2

dα1, α3]

= −[α3,LHα1α2 − iHα2

dα1]

= iH(LHα1α2−iHα2

dα1)dα3 − LHα3

(LHα1α2 − iHα2

dα1).

r ♣rès ♦r♦r ♦♥

H(LHα1α2 − iHα2

dα1) = [Hα1, Hα2].

Page 82: Structures de Poisson logarithmiques: invariants

♣tr ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

♦♥

[[α1, α2], α3]

= i[Hα1,Hα2]dα3 − LHα3

LHα1α2 + LHα3

iHα2dα1

= i[Hα1,Hα2]dα3 − LHα3

LHα1α2 + LHα3

LHα2− LHα3

diHα2α1

= i[Hα1,Hα2]dα3 − LHα3

LHα1α2 + LHα3

LHα2− dLHα3

iHα2α1.

.

Pr rs L ét♥t ♥ ♥♦♠♦r♣s♠ DerX(logD), s♥st q

[[α1, α2], α3]+ = i[Hα1,Hα2]dα3 + L[Hα3,Hα2]α1

− dLHα2iHα2

α1+

tr ♣rt ♦r♠ ♠q rt♥ t s étés ♣♣qés à α3 t

H(α2) ♦♥♥♥t

LHα2iHα2

α1 = i[Hα3,Hα2]+ iHα2

LHα3α1. tt r♥èr rt♦♥ ♥t q

−dLHα3iHα2

α1 = −d(LHα3

|Hα2

)− L[Hα3,Hα2]

α1 + i[Hα3,Hα2]dα1.

♥ sstt♥t −dLHα3iHα2

α1 ♥s ①♣rss♦♥ [[α1, α2], α3]+ sss ♦♥

♦t♥t

[[α1, α2], α3]+

= i[Hα1,Hα2]dα3 + L[Hα3,Hα2]

α1 − d(LHα3

|Hα2

)− L[Hα3,Hα2]

α1 + i[Hα3,Hα2]dα1+

= i[Hα1,Hα2]dα3 + i[Hα3,Hα2]

dα1 − d(LHα3

|Hα2

)+

= i[Hα1,Hα2]dα3 + i[Hα3,Hα2]

dα1 + i[Hα2,Hα3]dα1 + i[Hα1,Hα3]

dα2+

+i[Hα3,Hα1]dα2 + i[Hα2,Hα1]

dα3 − d((

LHα3|Hα2

)+

)

= d((

LHα3|Hα2

)+

)

r ♣rès é♦rè♠ (LHα3

|Hα2

)+ = 0.

♦ù réstt

♥ ♥ ét ss ♣r♦♣♦st♦♥ s♥t

Pr♦♣♦st♦♥ H st ♥ strtr èr ♥rt sr ΩX(logD)

Pr ❱♦r ♥♥①

♥♦s ♣♦s♦♥s Laltp(ΩX(logD)) s s p♦r♠s OX ♥érs ♥t

s②♠étrqs sr ΩX(logD) t

Lalt(ΩX(logD)) =n⊕p=0

Laltp(ΩX(logD)). ♦rs ♣♣t♦♥

(∂Df)(α1, ..., αp) =n∑i=1

(−1)i−1H(αi)f(α1, ..., αi, ..., αp)+∑i≤j

(−1)i+jf([αi, αj ], α1, ..., αi, ..., αj , ..., αp)

ér

♠♠ ∂2D = 0

Page 83: Structures de Poisson logarithmiques: invariants

①♠♣s s r♦♣s ♦♦♠♦♦s P♦ss♦♥

♦rt♠qs

Pr é♦ rt♦♥ t ♥tté ♦ r♦t

[−,−].

♥ rést q (Lalt∗(logD), ∂D) st ♥ ♦♠♣① ♥s ♥ ♥ ét

é♥t♦♥ s♥t

é♥t♦♥ ♦♦♠♦♦ ♦♠♣① (Lalt∗(logD), ∂D) st ♣♣é ♦♦

♠♦♦ P♦ss♦♥ ♦rt♠q rété P♦ss♦♥ ♦rt♠q X

kime r♦♣ ♦♦♠♦♦ ♦♠♣① sr ♥♦té HkPS(X) t kime r♦♣

♦♦♠♦♦ P♦ss♦♥ ss♦é sr ♥♦té HkP (X).

①♠♣s s r♦♣s ♦♦♠♦♦s

P♦ss♦♥

♦rt♠qs

r♦♣ ♦♦♠♦♦ P♦ss♦♥ ♦rt♠qs s strtrs ♦s②♠♣tqs

♦t (L, [−,−], ρ, I) ♥ èr ♥rt ♦rt♠q ♦♠♠ ♥s

❬♦♥♦ ❪ ♥♦s ♦♣t♦♥s é♥t♦♥ s♥t

é♥t♦♥ ♥ ♣♣ strtr èr ♥rt P♦ss♦♥ ♥s L ♦

rt♠q ♦♥ I t♦t ♦r♠ µ sr L dρr♠é

♦rsq µ st ♥ strtr èr ♥rt P♦ss♦♥ ♦rt♠q

(L, ρ, µ) st ♣♣é èr ♥rt P♦ss♦♥ ♦rt♠q ♥ r q

L st ♥ èr ♥rt P♦ss♦♥ ♦rt♠q ♦rsq ①st sr L ♥

strtr ♥rt P♦ss♦♥ sr L ♦rt♠q A st ♥ èr P♦ss♦♥

♦r♠ ss♦é ω, ♦rs

dH(ω) = 0

♥ t ♣♦r t♦t a, b, c ∈ A ♦♥

dH(ω)(da, db, dc) = H(da)ω(db, dc)−H(db)ω(da, dc) +H(dc)ω(da, db)

−ω(da, b, dc) + ω(da, c, db)− ω(db, c, da)= −2(Jacobi(a, b, c))

♥ ♦♥t ♦♥ q t♦t ♦r♠ P♦ss♦♥ sr A ♥t sr ΩA ♥ strtr

èr ♥rt P♦ss♦♥ ♥ st ♠ê♠ ♣♦r s ♦r♠s P♦ss♦♥

♦rt♠qs q ♥s♥t sr Ω1A(log I) s strtrs èr ♥rt

P♦ss♦♥ ♦rt♠qs

tt ♥♦t♦♥ strtr èr ♥rt P♦ss♦♥ ♦rt♠q st é

strtr èr ♥rtP♦ss♦♥s②♠♣tq ♦rt♠q

♥ P t réér♥ à ♥s P♦ss♦♥ ♦rs st ♠s ♣♦r ②♦ t♦

Page 84: Structures de Poisson logarithmiques: invariants

♣tr ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

é♥t♦♥ ♥ ♣♣ strtr èr ♥rtP♦ss♦♥s②♠♣tq

♦rt♠q ♥s L t♦t strtr èr ♥rt P♦ss♦♥

♦rt♠q µ sr L ♣♦r q ♣♣t♦♥

L → HomA(L,A)

x 7→ ıxµ

st ♥ s♦♠♦r♣s♠ A♠♦s

s♥ st q ♥s t♦t rété ♦s②♠♣tq (X,ω,D) ω st ♥ strtr

èr ♥rtP♦ss♦♥ s②♠♣tq ♦rt♠q sr DerX(logD).

♦s ♦♥s à ♣rés♥t ♠♦♥trr q s strtrs èr ♥rtP♦ss♦♥

s②♠♣tq ♦rt♠q s♦♥t ♥tèr♠♥t rtérsés ♣r H.

♦t µ ♦r♠ ss♦é à ♥ strtr P♦ss♦♥ ♦rt♠q ♣r♥♣ −,− ♦♥ ♥ é I A t µ ♥ strtr èr ♥rtP♦ss♦♥

s②♠♣tq ♦rt♠q

♥s st s strtrs èr ♥rts②♠♣tq ♦rt♠qs

sr♦♥t s♠♣♠♥t ♣♣é strtr èr ♥rt♦s②♠♣tq

Pr♦♣♦st♦♥ µ st ♥ strtr èr ♥rt♦s②♠♣tq

sr ΩA(log I) s t s♠♥t s H st ♥ s♦♠♦r♣s♠ A♠♦s

Pr ♣♣♦s♦♥s q H st ♥ s♦♠♦r♣s♠

♦t x, y ∈ ΩA(log I) ts q I(x) = I(y).

♦rs

−σ(H(x)) = I(x)

= I(y)

= −σ(H(y))

i.e. H(x) = H(y)

i.e. x = y

é♣r♦q♠♥t s♦t ψ ∈ H(ΩA(log I),A). r♦♥s x ∈ ΩA(log I) t q I(x) =ψ.

Psq ψ ∈ Hom(ΩA(log I),A) ∼= DerA(log I) = H(ΩA(log I)) ♦rs ①st

z ∈ ΩA(log I) t q H(z) = σ−1(ψ). ♥ ♦♥

I(−z) = σ(H(z)) = ψ.

st ♣r♥r x = −z.é♣r♦q♠♥t ♦♥ s♣♣♦s q I st ♥ s♦♠♦r♣s♠ ♦rs s H(x) = H(y),

♦rs −H(H(x)) = −H(H(y)); I(x) = I(y) t ♣r s♥t x = y.

Pr rs ♣♦r t♦t δ ∈ DerA(log I), ①st x ∈ ΩA(log I) t q

σ(δ) = I(x) = −σ(H(x)); H(−x) = δ.

Page 85: Structures de Poisson logarithmiques: invariants

①♠♣s s r♦♣s ♦♦♠♦♦s P♦ss♦♥

♦rt♠qs

♦♦♠♦♦ P♦ss♦♥ ♦rt♠q x, y = x

sr C[x, y]

♥t ♥r tt ♦♦♠♦♦ rér♦♥s qqs réstts

té♦rqs ♥tr♦ts ♥ st♦♥ ♦t ♦♥ tt st♦♥ A és♥r èr

C[x, y]. ♥ ♦♥sèr sr A r♦t

(f, g) 7→ f, g = x(∂f

∂x

∂g

∂y− ∂f

∂y

∂g

∂x)

q t A ♥ èr P♦ss♦♥ Pr rs ♣♦r t♦t f ∈ A, ért♦♥

Df := x(∂f

∂x

∂y− ∂f

∂y

∂x)

ér

Df (xA) ⊂ xA

st ♦♥ ♥ ért♦♥ ♦rt♠q ♣r♥♣ ♦♥ I = xA. ♥ ♥

ét ♦♥ q A st ♥ èr P♦ss♦♥ ♦rt♠q ♦♥ é xA.♦♠♠ t♦t strtr P♦ss♦♥ ♥t ♥ ♣♣t♦♥ A♥ér H : ΩA →DerA é♥ ♣r

H(df) = Df

♣♥♥t éqt♦♥ ♥♦s és♦♥s q H(ΩA) ⊂ Der(log xA) ♦ù

Der(log xA) st As♦s ♠♦ DerA ♦r♠é s ért♦♥s ♦rt♠qs

♦♥ I.♥ ♦♥

H(dx) = Dx = x∂

∂y, H(dy) = Dy = −x ∂

∂x

♦♥ r♠rq ss q

1

xDx(xA) =

∂y(xA) = x

∂y(A) ⊂ xA.

s♥st ♦♥ q1

xDx(xA) ∈ Der(log xA).

♦♥ ♦♥

H(dx

x) =

1

xH(dx) =

∂yt H(dy) = H(dy) = −x ∂

∂x

♠♠ s♥t ♥♦s ♣r♠t ♦♥r q s ♦♥♥és ss♥t ♣♦r é♥r

♥tèr♠♥t H.

♠♠

ΩA(log I) ∼= Adxx

⊕Ady ∼= C[y]dx

x⊕ ΩA.

Page 86: Structures de Poisson logarithmiques: invariants

♣tr ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

♥t ♦♥ q ♣♦r t♦t α ∈ ΩA(log I), ①st a, b ∈ A ts q

α = adx

x+ bdy.

♥ ♦t♥t ♦♥

H(adx

x+ bdy) = −bx ∂

∂x+ a

∂y∈ Der(log xA).

♥ é♥t ♥s ΩA(log I) r♦t

[α01

dx

x+ α1

1dy, α02

dx

x+ α1

2dy] :=(α01

xx, α0

2+α02

xα0

1, x+ α12α0

1, y+ α11y, α0

2)dx

x+

(α01

xx, α1

2+α02

xα1

1, x+ α11y, α1

2+ α12α1

1, y)dy .

♥ ♣r♦♣♦st♦♥ s♥t

Pr♦♣♦st♦♥ r♦t é♥ ♣r ♥t ♥ strtr èr

sr ΩA(log I).

Pr ❱♦r ♥♥①

♠rq

P♦r t♦t a(y)dx

x∈ C[y]

dx

xt bdx+ cdy ∈ ΩA, ♦♥

[a(y)dx

x, bdx+ cdy] = [a(y)

dx

x, bdx] + [a(y)

dx

x, cdy]

= a(y)(∂b

∂y− b

∂a(y)

∂y)dx+ a(y)

∂c

∂ydy ∈ ΩA

♥ ♦♥t q ΩA st st ♣♦r r♦t ΩA(log I). Pr rs

[a(y)dx

x, b(y)

dx

x] = (a(y)

∂b(y)

∂y− b(y)

∂a(y)

∂y)dx

x

t

[[a(y)dx

x, b(y)

dx

x], c(y)

dx

x]+ =

[(a(y)∂b(y)

∂y− b(y)

∂a(y)

∂y)dx

x, c(y)

dx

x]+ =

(a(y)(∂b(y)

∂y− b

∂a(y)

∂y)∂c(y)

∂y− ca

∂2b(y)

∂yy+ cb

∂2a(y)

∂yy)dx

x+

= 0

♦♥ C[y]dx

xst st ♣♦r r♦t [−,−].

♥s s ♣rtr ♣♣t♦♥ ♠t♦♥♥♥ ♦rt♠q ss♦é ér

♣r♦♣rété s♥t

Page 87: Structures de Poisson logarithmiques: invariants

①♠♣s s r♦♣s ♦♦♠♦♦s P♦ss♦♥

♦rt♠qs

♠♠ P♦r t♦t α = α01

dx

x+α1

1dy, β = β01dx

x+β11dy ∈ ΩA(log I) t a ∈ A,

♦♥

[α, aβ] = H(α)(a)β + a[α, β]

Pr ❱♦r ♥♥①

Pr♦♣♦st♦♥ H : ΩA(log I) −→ DerA(log xA) st ♥ ♦♠♦♠♦r♣s♠

èrs

Pr ❱♦r ♥♥①

P♦r ér s ♥♦tt♦♥s ♥♦s ♦♥sér♦♥s s s♦♠♦r♣s♠s s♥ts

Lalt0(ΩA(log I), I) ∼= A, Lalt1(ΩA(log I), I) ∼= DerA(log I) ∼= A × A t

Lalt2(ΩA(log I), I) ∼= A. s r♥rs ♦♠♣① P♦ss♦♥ ♦

rt♠q ss♦é ♥t

0 // Ad0H // A×A

d1H // A // 0

ou d0H(f) = (∂yf,−x∂xf) t d1H(f1, f2) = ∂yf2 + x∂xf1.

♥ ♥

d1H(d0Hf) = x(∂2xyf − ∂2xyf) = 0.

q ♠♦♥tr q dH st rré ♥

Pr♦♣♦st♦♥ ♦r♠ P♦ss♦♥ ss♦é à x, y = x st ♦s②♠♣

tq

Pr

Pr é♥t♦♥ ♦r♠ P♦ss♦♥ −,− st µ = x∂x ∧ ∂y. ♥ ♥ ét q

♦r♠ ♦rrs♣♦♥♥t à µ st ω =dx

x∧ dy q st ♥ ♦s②♠♣tq

♦s ♦♥s à ♣rés♥t r s r♦♣s ♦♦♠♦♦ ss♦és

Pr♦♣♦st♦♥ H0PS

∼= C H1PS

∼= C H2PS

∼= 0A.

Pr ♣rès é♥t♦♥ ér♥t dH , ♦♥

H0PS .

P♦r f ∈ A. f ∈ ker d0H

s t s♠♥t s∂f

∂y=∂f

∂x= 0.

s♥st q Kerd0H

∼= C.

H2PS .

P♦r t♦t g ∈ A ♦♥ g = d1H(0,

∫gdy+ k(x)). ♦♥ d1

Hst ♥ é♣♠♦r♣s♠

t ♣r st H2PS

∼= OA.

H1PS . ♥ r♠rq q A2 ∼= (C[y]× C[x])⊕ (xA× yA).

♥s ♣♦r t♦t (f1, f2) ∈ A × A, ①st g1 ∈ C[y], g2 ∈ C[x], h2, h1 ∈ At q f1 = g1(y) + xh1 t f2 = g2(x) + yh2. s ♣♦r t♦t (a(y), b(x)) ∈

Page 88: Structures de Poisson logarithmiques: invariants

♣tr ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

C[y]×C[x], x∂a(y)

∂x+∂b(x)

∂y= 0. ♦♥ C[y]×C[x] ⊂ ker d1

H. P♦r s rs♦♥s

♥♦s ♥♦s ♦♥s

ker(d1H) : = ker(d1

H) ∩ A2

= (C[y]× C[x])⊕ ker(d1H) ∩ (xA× yA)

= (C[y]× C[x])⊕Θ(A)

♦ù Θ st é♥ ♣r

A Θ // A2 a 7→ (xa,−∫x∂xa

∂xdy)

Pr rs Θ(A) ⊂ ker(d1H) t

A ∼= C[x]⊕ yC[y]⊕ xyA.

♥ ♥ ét q ♣♦r t♦t f ∈ A, ①st (f1, q, p) ∈ C[x] × C[y] × A t

q f = f1 + yq + xyp.

♥s∂f

∂y= q+y

∂q

∂y+x(p+y

∂p

∂y) = (1+y

∂y)q+x(1+y

∂y)p ∈ C[y]⊕x(1+y ∂

∂y)(A)

t

−x∂f∂x

= −x∂f1∂x

− xyp− x2y∂p

∂x= −x∂f1

∂x− xy(1 + x

∂x)p ∈ xC[x]⊕ xy(1 +

x∂

∂x)A.

♥ ♦♥sèr Ψ : A → A2, f 7→ (x(1 + y∂

∂y)f,−xy(1 + x

∂x)f)

Psq

(x(1 + y∂

∂y)f,−xy(1 + x

∂x)f) = (xf

∂y

∂y+ xy

∂f

∂y,−x∂x

∂xyf − x2

∂yf

∂x)

= (∂xyf

∂y,−x∂xyf

∂x)

= d0H(xyf)

t Ψ(A) ⊂ d0H(A). ♥

(∂f

∂y,−x∂f

∂x) ∈ (C[y]× xC[x])⊕Ψ(A)

é♣r♦q♠♥t ♣♦r t♦t F := (f1(y), xf2(x)) + Ψ(p) ∈ (C[y] × xC[x]) ⊕Ψ(A), ♥

F = d0H(

∫f1dy−

∫f2dx)+d

0H(xyp) = d0

H(

∫f1dy−

∫f2dx+xyp) ∈ d0

H(A)

♦♥

d0H(A) ∼= (C[y]× xC[x])⊕Ψ(A)

Page 89: Structures de Poisson logarithmiques: invariants

①♠♣s s r♦♣s ♦♦♠♦♦s P♦ss♦♥

♦rt♠qs

tr ♣rt t q d0H(∫xady) = (xa,−

∫x∂xa

∂xdy) ♣♦r t♦t a ∈ A,

♦♥ ♥ ét q Θ(A) ⊂ d0H(A). ♣s ♣r ♥ rt ♥♦s ♦♥♥

Θ(A) ⊂ Ψ(A).

Psq (C[y]×C[x]) ∼= (C[y]×xC)⊕ (0A×C) t x∂A∂x

∩C = 0A, ♦♥ ♦♥

d0H(A) ∩ (0A × C) ∼= 0A.

♦ù

H1PS

∼= C.

♣rès s Pr♦♣♦st♦♥s t s ♦♦♠♦♦s P♦ss♦♥ ♠

♦rt♠qs t P♦ss♦♥ ♦rt♠qs ss♦és à strtr P♦ss♦♥

x, y = x s♦♥t s♦♠♦r♣s ♣r♦♣♦st♦♥ s♥t ♥♦s ♣r♠t érr

réstt ♥s s strtr P♦ss♦♥ ♦rt♠q ♣r♥♣ x, y = x.

Pr♦♣♦st♦♥ s r♦♣s ♦♦♠♦♦s P♦ss♦♥ x, y = x s♦♥t

H0P∼= C H1

P∼= C t H2

P∼= 0A.

Pr rs ♦♠♣① ♠ ♦rt♠q ♦♥ I st

0 // A d0 // Ω1A(log xA)

d1 // Ω2A(log xA) // 0

♦ù

d0(a) := x∂x(a)dx

x+ ∂y(a)dy

t

d1(adx

x+ bdy) := (x∂x(b)− ∂y(a))

dx

x∧ dy.

Pr♦♣♦st♦♥ r♠♠ s♥t st ♦♠♠tt

0 // A

d0 // ΩA(log xA)

−H

d1 // Ω2A(log xA)

−H

// 0

0 // Ad0H // A2

d1H // A // 0

Pr P♦r t♦t a ∈ A ♥♦s ♦♥s H(da) = H(x∂x(a)dx

x+ ∂y(a)dy) =

−∂y(a)x∂x + x∂x(a)∂y ∼= (−∂y(a), x∂x(a)) t d0H(a) ∼= (∂y(a),−x∂x(a)) = −H(da)

♣s ♣♦r t♦t α = fdx

x+gdy ∈ ΩA(log I), ♦♥ d1(α) = (x∂x(g)−∂y(f))

dx

x∧

dy, −H(d1(α)) ∼= x∂x(g)− ∂y(f).

Pr rs −H(α) = gx∂x − f∂y ∼= (g,−f) ♥♦s ♦♥s d1H(−H) = d1

H(gx∂x −

f∂y) ∼= x∂x(g)− ∂y(f)

♣r♦♣♦st♦♥ s♥t ♦♥♥ s r♦♣s ♦♦♠♦♦ ss♦és à ♦♠♣①

Pr♦♣♦st♦♥ s r♦♣s ♦♦♠♦♦ ♦♠♣① s♦♥t H0DS

∼=C H1

DS∼= C t H2

DS∼= 0A.

Page 90: Structures de Poisson logarithmiques: invariants

♣tr ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

Pr

P♦r s♠♣r s ♥♦tt♦♥s ♥♦s ♣♦s♦♥s

Ω1A(log xA)

∼=→ A×Aadx

x+ bdy 7→ (a, b)

Ω2A(log xA)

∼=→ Aadx

x∧ dy 7→ a

s ♥♦tt♦♥s ♦♠♣① ♥t

0 // A d0 // A×A d1 // A // 0

♦ù d0(f) = (x∂xf, ∂yf) t d1(f1, f2) = x∂xf2 − ∂yf1.

P♦r t♦t f ∈ A, ♦♥ f = d1(−∫fdy, 0). ♦♥ A ∼= d1(A × A) t ♣r st

H2DS

∼= 0.

Pr ♥ s♠♣ ♦♥ ♦t♥t H0DS

∼= C.

♦t (f1, f2) ∈ A×A. (f1, f2) ∈ ker(d1) s t s♠♥t s f1 = x∫∂xf

2dy + k(x).

♦♥ ker(d1) ∼= (x∫∂xudy, u);u ∈ A ⊕ xC ⊕ C. r ♣♣t♦♥ s♥t st ♥

♠♦♥♦♠♦r♣s♠ ♠♦s

θ : A → xA×Au 7→ (x

∫∂xudy, u)

t ker(d1) ∼= θ(A)⊕ (xC× 0A) ∼= θ(A)⊕ (xC⊕ C).

♣s ♣♦r u ∈ A t a ∈ C[x], ♦♥

d0(∫udy+

∫adx) = (x

∫∂xudy+xa, u) = (x

∫∂xudy, u)+(xa, 0) = θ(u)+(xa, 0) ∈

θ(A)⊕ (xC). ♦♥ θ(A)⊕ (xC) ⊂ d0(A). Psq C ∩ d0(A) = 0A ♦♥ d0(A) =

d0(A)∩ (ker(d1)) ∼= θ(A)⊕ (xC). ♦♥ ker(d1) ∼= d0(A)⊕C. t ♦♥ H1DS

∼= C.

s ♦♦♠♦♦s P♦ss♦♥ t P♦ss♦♥ ♦rt♠q

(A := C[x, y], x, y = x2)).

♥s tt st♦♥ ♥♦s ♣r♦♣♦s♦♥s ♥ ①♠♣ strtr P♦ss♦♥ ♥♦♥

♦s②♠♣tq t ♥♦s ♠♦♥tr♦♥s q ss r♦♣s ♦♦♠♦♦s P♦ss♦♥ t

P♦ss♦♥ ♦rt♠q s♦♥t s♦♠♦r♣s

♥ ♦♥sèr ♥sA = C[x, y] r♦t P♦ss♦♥ x, y = x2 q st ♣r é♥t♦♥

♦rt♠q ♣r♥♣ ♦♥ é A = C[x, y] ♥♥ré ♣r x2. ♦t♦♥s

qdx2

x2= 2

dx

x. ♦♥ ΩA(log x

2A) st s♦♠♦r♣ A♠♦ ♥♥ré ♣r dxx

∪ΩA

♦♦♠♦♦ P♦ss♦♥ ♦rt♠q A = C[x, y], x, y = x2.

♣♣t♦♥ ♠t♦♥♥♥ ♦rt♠q ss♦é st é♥ sr s é♥ér

trs ΩA(log x2A) ♣r H(

dx

x) = x∂y, H(dy) = −x2∂x. ♥ ♥ ét ♦♠♣①

P♦ss♦♥ ♦rt♠q s♥t

0 // Ad0H(H) // A×A

d1H // A // 0

Page 91: Structures de Poisson logarithmiques: invariants

①♠♣s s r♦♣s ♦♦♠♦♦s P♦ss♦♥

♦rt♠qs

♦ù d∗H

st é♥ ♣r d0H(f) = (x∂yf,−x2∂xf), d1H(f1, f2) = x∂yf2 + x2∂xf1 − xf1

t s s♦♠♦r♣s♠s s♥ts s♦♥t s♦s♥t♥s

DerA(log x2A)

∼=→ A×Aax∂x + b∂y 7→ (a, b)

DerA(log x2A) ∧DerA(log x2A)

∼=→ Aax∂x ∧ ∂y 7→ a

H2PS (A := C[x, y], x, y = x2).

Psq A ∼= C[y] ⊕ xA ♦rs ♣♦r t♦t g ∈ A, ①st g1, g2 ∈ A t q

g = g1 + xg2. ♥s ♣♦r t♦t g ∈ A ♦♥ g ∈ d1H(A) s t s♠♥t s g = xg2 =

x∂yf2 + x2∂xf1 − xf1. s xg2 = x∂y(x∫∂xg2dy) − x2∂xg2 − xg2 t éqt♦♥

x(∂yv + x∂xu − u) = g(y) ∈ C[y]∗ ♥ ♣♦ssè ♣s s♦t♦♥ ♥s A × A. ♦♥

A ∼= d1H(A×A)⊕ C[y]. s♥st q

H2PS

∼= C[y].

H1PS .

P♦r r H1PS ♥♦s ♦♥s s♦♥ ♠♠ s♥t

♠♠ ♦t ϕ : E → F ♥ ♠♦♥♦♠♦r♣s♠ s♣s t♦rs P♦r t♦t

s♦s ♥s♠ A,B E,ϕ(A⊕B) = ϕ(A)⊕ ϕ(B)

Pr st r q ϕ(A ⊕ B) = ϕ(A) + ϕ(B). z ∈ ϕ(A) ∩ ϕ(B), ♦rs

z ∈ ϕ(A⊕B) = 0E . Pr st ϕ(A⊕B) = ϕ(A)⊕ ϕ(B).

♦t (f1, f2) ∈ A×A.(f1, f2) ∈ ker(d1

H) s t s♠♥t s ①st k ∈ C[x] t q f2 =

∫(1−x∂x)f1dy+

k(x). ♥s ker(d1H) ∼= (u,

∫(1 − x∂x)udy), uA ⊕ C[x]. P♦r t♦t u ∈ A ♦♥ ♣♦s

η(u) = (u,∫(1− x∂x)udy). ♦♥ η : A → A×A st ♥ ♠♦♥♦♠♦r♣s♠ s♣s

t♦rs ker(d1H) ∼= η(A)⊕C[x] ∼= η(C[y])⊕η(xA)⊕C[x]; ♣sq A ∼= C[y]⊕xA.

tr ♣rt ♣♦r t♦t g ∈ η(xA) ⊕ (0A, x2C[x]), ①st u ∈ A t v ∈ C[x] ts

q g = (xu,−x2∫∂xdy + x2v(x)) = d0

H(∫udy −

∫v(x)dx). ♣s ♣♦r t♦t

u(y) ∈ C[y] t a0, a1 ∈ C, éqt♦♥ ér♥t

xfy = u(y)

−x2fx =∫u(y)dy + a0 + a1x

♥ ♣♦ssè ♣s s♦t♦♥ ♥s A. ♦♥ ker(d1H) ∼= η(C[y])⊕ C1[x]⊕ d0

H(A). Pr

st

H1PS

∼= η(C[y])⊕ C1[x].

♦ù C1[x] := a0 + a1x; a0, a1 ∈ C. tr ♣rt ♣sq η st ♥ ♠♦♥♦♠♦r♣s♠

η(C[y]) ∼= C[y]. ♦rs

H1PS

∼= C[y]⊕ C1[x].

è ♣r ♣r♦♣♦st♦♥ s♥t

Pr♦♣♦st♦♥ s r♦♣s ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

x, y = x2 s♦♥t

H1PS

∼= C[y]⊕ C1[x];H2PS

∼= C[y], H0PS

∼= C.

Page 92: Structures de Poisson logarithmiques: invariants

♣tr ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

♦♦♠♦♦ P♦ss♦♥ A = C[x, y], x, y = x2.

t♦♥ ♣♣t♦♥ ♠t♦♥♥♥ ss♦é sr s é♥értrs ΩA st

H(dx) = x2∂y t H(dy) = −x2∂x.♣r s♦ s♠♣té ♥♦s ♦♣t♦♥s s s♦♠♦r♣s♠s s♥t

DerA∼=→ A×A

a∂x + b∂y 7→ (a, b)

DerA ∧DerA∼=→ A

a∂x ∧ ∂y 7→ a.

s s♦♠♦r♣s♠s ér♥t ♦♦♠♦♦ P♦ss♦♥ ♥t

d0H(f) = (x2∂yf,−x2∂xf) t d1H(f1, f2) = x2∂xf1 + x2∂yf2 − 2xf1.

P♦r t♦t g ∈ A, ♥♦s ♦♥s xg = −2x(−1

2g) + x2(

1

2)(−∂xg + ∂y(

∫∂xgdy)).

♦♥ A ∼= d1H(A×A)⊕ C[y].

Pr st

H2P∼= C[y].

♦t (f1, f2) ∈ A×A

(f1, f2) ∈ ker(d1H) s t s♠♥t s u ∈ A, a ∈ C[x]. stàr f1 = xu t

f2 =∫(1− x∂x)udy + a(x).

♦♥ ker(d1H) = (xu,∫(1 − x∂x)udy + a(x)), u ∈ A, a(x) ∈ C[x]. ♥ ♣♦s

ϕ(u) = (xu,∫(1 − x∂x)udy ♣♦r t♦t u ∈ A. ♦rs ϕ : A → xA × A st ♥

s♦♠♦r♣s♠ s♣s t♦rs t

ker(d1H)∼= ϕ(A)⊕ C[x]

tr ♣rt ♦♠♣t t♥ t q A ∼= C[y]⊕xA, ♦♥ ϕ(A) ∼= ϕ(C[y])⊕ϕ(xA).

Pr rs ϕ(xA)⊕ x2C[x] ⊂ d0H(A), t ♦♥ d0H(A) ∩ ϕ(C[y])⊕ C1[x] ∼= 0APr st

ker(d1H)∼= ϕ(C[y])⊕ C1[x]⊕ d0H(A) ∼= C[y]⊕ C1[x]⊕ d0H(A)

♥ ♥ ét q

H1P∼= C[y]⊕ C1[x]

è ♣r ♣r♦♣♦st♦♥ s♥t

Pr♦♣♦st♦♥ s r♦♣s ♦♦♠♦♦ P♦ss♦♥ x, y = x2 s♦♥t

H1P∼= C[y]⊕ C1[x];H

2P∼= C[y], H0

P∼= C

♥ ét é♥t♦♥ s ér♥ts ♦r♠s ♦rt♠qs ♦♥ x2At xA q ΩA(log x

2A) ∼= ΩA(log xA). ♥s ♦r♠ ω =dx

x2∧ dy ss♦é à

♦r♠ P♦ss♦♥ x2∂

∂x∧ ∂

∂y x, y = x2 ♥st ♣s ♦rt♠q t♥t

♣s q1

x/∈ C[x, y]. Pr rs ♦♠♦♠♦r♣s♠ ♠♦s s♥t

µ : ΩA(log x2A) → HA(ΩA(log x

2A),A), α0dx

x+ α0dy 7→ −α1x

2 ∂

∂x+ xα0

∂y

Page 93: Structures de Poisson logarithmiques: invariants

①♠♣s s r♦♣s ♦♦♠♦♦s P♦ss♦♥

♦rt♠qs

♥st ♣s srt

♥ t −1

xdy st ♥q ♥téé♥t x

∂xq ♥st ♣♥♥t ♣s éé♠♥t

ΩA(log x2A) s ♦♥ ♦♥sèr ♥♦tr é♥t♦♥ s ér♥ts ♦r♠s ♦rt

♠qs s♥st q x, y = x2 st ♥ strtr P♦ss♦♥ ♦rt♠q

♣r♥♣ ♥♦♥ ♦s②♠♣tq ♥ ♦t♥t ♦♥ té♦rè♠ s♥t

é♦rè♠ r♦t x, y = x2 ♥t sr C[x, y] ♥ strtr P♦s

s♦♥ ♦rt♠q ♣r♥♣ ♦♥ é x2A. tt strtr P♦ss♦♥ ♥st

♣s ♦s②♠♣tq ♠s ss r♦♣s ♦♦♠♦♦ P♦ss♦♥ t P♦ss♦♥ ♦

rt♠qs s♦♥t s♦♠♦r♣s

♦♦♠♦♦ P♦ss♦♥ t P♦ss♦♥ ♦rt♠q strtr P♦ss♦♥ x, y = 0, x, z =0, y, z = xyz sr A = C[x, y, z]

♥s tt ♣rt ♥♦s ♠♦♥tr♦♥s q strtr P♦ss♦♥ ♦rt♠q

♣r♥♣A = C[x, y, z] ♥st ♣s ♦s②♠♣tq t q ss r♦♣s ♦♦♠♦♦

t ① P♦ss♦♥ t P♦ss♦♥ ♦rt♠q ss♦és s♦♥t ér♥ts Pr é♥t♦♥

tt strtr P♦ss♦♥ st ♦rt♠q ♣r♥♣ ♦♥ é xyzA t s

ér♥ts P♦ss♦♥ ♦rt♠qs s♦♥t

d0H(f) = (0, xz

∂f

∂z,−xy∂f

∂y)

d1H(f1, f2, f3) = (xz

∂f3∂z

+ xy∂f2∂y

− xf1,−xy∂f1∂y

,−xz∂f1∂z

)

d2H(f1, f2, f3) = xz

∂f2∂z

+ xy∂f3∂y

.

♠ê♠ s ér♥ts P♦ss♦♥ ss♦és s♦♥t

δ0(f) = xyz(0,∂f

∂z,−∂f

∂y)

δ1(f1, f2, f3) = (xyz∂f3∂z

+ xyz∂f2∂y

− yzf1 − xzf2 − xyf3,−xyz∂f1∂y

,−xyz∂f1∂z

)

δ2(f1, f2, f3) = xyz(∂f2∂z

+∂f3∂y

).

H3PS

♦s és♦♥s s éqt♦♥s q d2H(A3) ⊂ xA.

♣♥♥t

A ∼= C[y]⊕ zC[z]⊕ xA∼= C[y]⊕ zC[z]⊕ xC[x]⊕ xyC[y]⊕ xzC[z]⊕ x2yA⊕ x2zA⊕ xyzA.

t ♣r ♦♥tr s♥r q ♣rès é♥t♦♥ ♦r♠ ér♥t ♦rt♠q

♦♥♥é ♥s ❬t♦ ❪ −dy

xst ♥ ♥ ♦r♠ ér♥t ♦rt♠q

Page 94: Structures de Poisson logarithmiques: invariants

♣tr ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

tr ♣rt ♣♦r t♦t xg(x) ∈ xC[x] éqt♦♥ ér♥t z∂u

∂z+y

∂v

∂y= g(x) ♥

♣♦ssè ♣s s♦t♦♥ ♥s A×A×A ♣s ♣♦r t♦t g ∈ xyC[y]⊕ xzC[z]⊕x2yA⊕ x2zA⊕ xyzA, ①st

g1(y), g2(z), g3(x, y, z), g4(x, y, z), g5(x, y, z) ∈ At q g = xyg1(y) + xzg2(z) + x2yg3(x, y, z) + x2zg4(x, y, z) + xyzg5(x, y, z)

♥ ♥ ét ①♣rss♦♥ s ♦♦rs

z∂f2∂z

+ y∂f3∂y

= yg1(y)+ zg2(z)+xyg3(x, y, z)+xzg4(x, y, z)+ yzg5(x, y, z)

q st éq♥t à

z(∂f2∂z

−g2(z)−xg4(x, y, z))+y(∂f3∂y

−g1(y)−xg3(x, y, z)−zg5(x, y, z)) = 0

st ♦♥ ♣r♥r

f2 =

∫g2(z) + xg4(x, y, z)dz; f3 =

∫g1(y) + xg3(x, y, z) + zg5(x, y, z)dy

♣♦r ♦r

d2H(A3) ∼= xyC[y]⊕ xzC[z]⊕ x2yA⊕ x2zA⊕ xyzA.

♥ ♥ ét q

H3PS

∼= C[y]⊕ zC[z]⊕ xC[x].

H3P .

éqt♦♥ ♥♦s és♦♥s q

δ2(A3) ⊂ xyzA.

sA ∼= C[y]⊕ zC[z]⊕ xC[x]⊕ xyC[y]⊕ xyC[x]⊕ xzC[x]⊕

xzC[z]⊕ yzC[y]⊕ yzC[z]⊕ xyzA

tδ2(A3) ∩ C[y]⊕ zC[z]⊕ xC[x]⊕ xyC[y]⊕ xyC[x]⊕

xzC[x]⊕ xzC[z]⊕ yzC[y]⊕ yzC[z] ∼= 0A

Psq ♠♦r♣s♠

A×A → A, (u, v) 7→ ∂u

∂z+∂v

∂y

st srt δ3(A3) ∼= xyzA,♦rs

H3P∼= C[y]⊕ zC[z]⊕ xC[x]⊕ xyC[y]⊕ xyC[x]⊕xzC[x]⊕ xzC[z]⊕ yzC[y]⊕ yzC[z]

♥ ♦♥t q

Page 95: Structures de Poisson logarithmiques: invariants

①♠♣s s r♦♣s ♦♦♠♦♦s P♦ss♦♥

♦rt♠qs

é♦rè♠ tr♦sè♠ r♦♣ ♦♦♠♦♦ P♦ss♦♥ ♦rt♠q

strtr P♦ss♦♥ (A = C[x, y, z], x, y = 0, x, z = 0, y, z = xyz)

stH3P∼= C[y]⊕ zC[z]⊕ xC[x]⊕ xyC[y]⊕ xyC[x]⊕xzC[x]⊕ xzC[z]⊕ yzC[y]⊕ yzC[z]

tr♦sè♠ r♦♣ ♦♦♠♦♦ P♦ss♦♥ strtr P♦ss♦♥

(A = C[x, y, z], x, y = 0, x, z = 0, y, z = xyz) st

H3PS

∼= C[y]⊕ zC[z]⊕ xC[x]

♥ ♥ H3PS 6= H3

P .

Page 96: Structures de Poisson logarithmiques: invariants
Page 97: Structures de Poisson logarithmiques: invariants

♣tr

Préq♥tt♦♥ s strtrs

P♦ss♦♥

♦rt♠qs

♦♠♠r Préq♥tt♦♥ s strtrs ♦s②♠♣tqs

qs ♣r♦♣rétés s strtrs ♦s②♠♣tqs

♦♥♥①♦♥ ♦rt♠q

♥trté s ♦r♠s ♦rt♠qs r♠és

Préq♥tt♦♥ s strtrs P♦ss♦♥ ♦rt♠qs

qs r♠rqs sr ♦♦♠♦♦ s rétés P♦ss♦♥

♦rt♠qs

ss r♥P♦ss♦♥ ♦rt♠q

①♠♣s ♣♣t♦♥s

Préq♥tt♦♥ (C2, π = z1∂z1 ∧ ∂z2)

Préqtt♦♥ CP1 ♠♥ strtr

♥tr♦t♦♥

♥s ♣tr ♥♦s ét♦♥s s ♦♥t♦♥s ♥térté s strtrs

♦s②♠♣tqs t ♣réq♥tt♦♥ s strtrs P♦ss♦♥ ♦rt♠qs

Préq♥tt♦♥ s strtrs ♦s②♠♣tqs

♥s tt ♣rt A és♥ ♥ èr ♦♠♠tt ♥tr sr ♥ ♦r♣s k

rtérstq 0 t I ♥ é ♣r♦♣r A ♥♥ré ♣r S = u1, ..., up ⊂ A.

qs ♣r♦♣rétés s strtrs ♦s②♠♣tqs

♦t µ ♥ strtr èr ♥rt♦s②♠♣tq sr DerA(log I).P♦r t♦t a ∈ A ①st ♥ ♥q ért♦♥ ♣r♥♣ δa t q

i(δa)µ = da.

Page 98: Structures de Poisson logarithmiques: invariants

♣tr Préq♥tt♦♥ s strtrs P♦ss♦♥

♦rt♠qs

P♦s♦♥s

a, b = −µ(δa, δb)

♣♦r t♦t a, b ∈ A. ♥ ♦t♥t ♥s ♥ r♦t P♦ss♦♥ −,− sr A. ♣s

♣♦r t♦t ui ∈ S, ①st ♥ ♥q δui ∈ Derk(log I) t q

iδuiµ =

duiui.

Psq dui ∈ ΩA ⊂ ΩA(log I), ①st δui t q iδuiµ = dui.

♥ ♦♥sèr r♦t s♥t

a, bsing :=

1

uvu, v a = u, b = v ∈ S

1

uu, b a = u ∈ S, b ∈ A− S

a, b a, b ∈ A− S

Pr♦♣♦st♦♥ ♦t strtr èr ♥rt ♦s②♠♣tq µ sr

A, ♥t ♥s A ① strtrs èrs −,− t −,−sing é♥s

♦♠♠ sss s strtrs ér♥t s ♣r♦♣rétés s♥ts

i(δu,v−uvδu,vsing)µ = u, v

(du

u+dv

v

),

uv, asing = u+ v, asing; ∀a ∈ A− I, a, b = δa(b),

[δa, δb] = δa,b,

δu,v = uv[δu, δv] + u, v(δv + δu).

Pr P♦r t♦s u, v ∈ I, ♦♥

i(δu,v−uvδu,v)µ = iδu,vµ− ıuvδu,vµ

= du, v − uvd(1

uvu, v)

= u, v(du

u+dv

v

).

♦ù ♣r♦♣rété

P♦r q st ♣r♦♣rété ♥♦s r♠rq♦♥s q

i(uv[δu,δv ]+u,v(δu+δv))µ = uvi([δu,δv ])µ+ u, v(du

u+dv

v

= uvi[δu,δv ]µ+ i(δu,v−uvδu,vsing

= i(uv[δu,δv ]+δu,v−uvδu,vsing

)µ.

st ♠♦♥trr q

i(uv[δu,δv ])µ = i(uvδu,vsing

)µ.

Page 99: Structures de Poisson logarithmiques: invariants

Préq♥tt♦♥ s strtrs ♦s②♠♣tqs

ri(uv[δu,δv ])µ = uvi([δu,δv ])µ

= uv[Lδu , iδv ]µ= uv

(Lδuiδvµ− iδvLδuµ

)

= uvd

(1

uvu, v

).

Pr rsi(uvδu,vsing

)µ = uvi(δu,vsing

= uvd (u, vsing)= uvd

(1

uvu, v

).

♦ù été ré t ♣r♦♣rété st ♥s é♠♦♥tré

♦♥♥①♦♥ ♦rt♠q

♦♥t L,L′ t L′′ tr♦s èrs ♥rt

L′′ st ♥ ①t♥s♦♥ L ♦♥ L′ s ①st ♥ st ①t ♦rt

0 // L′f // L

g // L′′ // 0

èrs ♥rt

♦t ①t♥s♦♥ t②♣ ♥t ♥ ♣♣t♦♥ ♥ér ω : L′′ → L t q

g ω = id

①t♥s♦♥ st s♥é s ω st ♥ ♦♠♦♠♦r♣s♠ èrs ♥rt

♦t ①t♥s♦♥ t②♣ ♥t ① ♣♣t♦♥s

α : L′′ −→ EndK(L′)

x 7→ αx : y 7→ [ω(x), y]

Ω :2∧L′′ −→ L′

(x; y) 7→ [ω(x), ω(y)]− ω([x, y])

ts q

[αx;αy]− α[x,y] = [ω(x, y),−]

cyclerx,y,z

(αxω(x, y)− ω([x, y], z)) = 0

é♦rè♠ ❬s♠♥♥ ❪❬é♦rè♠ ❪

♦♥t L′ t L′′ ① èrs ♥rt L′ é♥♥ t s♦t : L′′ →End(L′) ♥ strtr ♠♦ ♥rt L′′ sr L′. ♦rrs♣♦♥♥

Page 100: Structures de Poisson logarithmiques: invariants

♣tr Préq♥tt♦♥ s strtrs P♦ss♦♥

♦rt♠qs

q à t♦t ss s♦♠♦r♣s♠ ①t♥s♦♥ t②♣ ss♦ ss Ω ∈Lalt2A(L′′, L′), st ♥ t♦♥ ♥tr ♥s♠ s sss ①t♥s♦♥s s♥és

L′ ♣r L′′ t H2(LaltA(L′′, L′)).

♦♥t L ♥ èr ♥rt t M ♥ A♠♦

❯♥ L♦♥♥①♦♥ ♥sM st ♥ ♣♣t♦♥ k♥ér ∇ : L→ End(M) t q

∇(aα)(m) = a(∇(α))(m)

∇(α)(am) = a∇(α)(m) + (ρL(α))(a)m.

s DerA(log I)♦♥♥①♦♥s sr M s♦♥t ♣♣és ♦♥♥①♦♥s ♦rt♠qs ♦♥

I sr M.

♦t L♦♥♥①♦♥ ∇ sr M ♥t ♥ ♣♣t♦♥ A♥ér

∇ :M → HomA(L,M) é♥ ♣r

∇α(m) := (∇(α))(m).

♣s ∇ ♥t sr LaltA(L,M) ♦♣értr

(d∇f)(α0, ..., αp) =i=p∑i=0

(−1)i∇αif(α0, ..., αi, ..., αp)+∑i<j

(−1)i+jf([αi, αj ], α0, ..., αi, ..., αj , ..., αp).

s♥st q ♣♦r t♦t L♦♥♥①♦♥ ∇ sr M,

(d∇f)(α0, α1) = ∇α0(f(α1))− ∇α1(f(α0))− f([α0, α1]

= (∇(α0))(f(α1))− (∇(α1)(f(α0)))− f([α0, α1]);

♣♦r t♦t α1, α2 ∈ L.

♥ ♥ ét q

(d∇∇(m))(α0, α1) = ∇α0(f(α1))− ∇α1(f(α0))− f([α0, α1]

d∇ d∇(m)(α0, α1) = (∇(α0))(f(α1))− (∇(α1)(f(α0)))− f([α0, α1])

= (∇(α0))(∇(m)(α1))− (∇(α1)(∇(m)(α0)))− ∇(m)([α0, α1])

= (∇(α0))(∇(α1)(m))− (∇(α1)(∇(α0)(m)))−∇([α0, α1])(m)

= ((∇(α0))(∇(α1))− (∇(α1)(∇(α0)))−∇([α0, α1]))(m)

= ([∇(α0),∇(α1)]−∇([α0, α1]))(m).

♥ ♥ ét ♣♣t♦♥ ♥ér ♥ts②♠étrq

ΩM L× L → End(M)

(α1, α2) 7→ [∇(α0),∇(α1)]−∇([α0, α1]

é♥t♦♥ ΩM st ♣♣é ♦rr L♦♥♥①♦♥ ∇ sr M.

♦t♦♥s Pic(A) r♦♣ s sss s♦♠♦r♣s♠s A♠♦s ♣r♦ts

r♥ 1.

Page 101: Structures de Poisson logarithmiques: invariants

Préq♥tt♦♥ s strtrs ♦s②♠♣tqs

é♦rè♠ ❬s♠♥♥ ❪ P♦r t♦t èr ♥rt L, ♣

♣t♦♥

C : Pic(A) → H2(LaltA(L,A))

M 7→ [ΩM ]

st ♥ ♦♠♦♠♦r♣s♠ A♠♦s

P♦r L = DerA(log I) té♦rè♠ ♠♣q q ♣♣t♦♥

C : Pic(A) → H2(LaltA(DerA(log I),A))

M 7→ [ΩM ].

st ♥ ♠♦r♣s♠ A♠♦s ♥s s ΩM st ♥ ♦r♠ ♦rt♠q

♦♥ I♦♥t X ♥ rété ♦♠♣① ♠♥s♦♥ n s r♠s ♦♥t♦♥s

♦♦♠♦r♣s OX t D ♥ sr rét t r X.

♦s ♥t♦♥s t♦t ré ♥ r♦t ♦♠♣① p : L→ X s F := F(L)

OX ♠♦ ss st♦♥s

♦t F ♥ ♥ ré ♥ r♦t ♦♠♣① sr X ❯♥ ♦♥♥①♦♥ ♥s F à ♣ôs ♦

rt♠qs ♦♥ D st ♥ ♦♠♦♠♦r♣s♠ C−♥ér

: F → Ω1X(logD)⊗F

ér♥t rè ♥③ s♥t

∇(fs) = df ⊗ s+ f∇(s)

Pr♦♣♦st♦♥ ♦t ♦♥♥①♦♥ ♥s F , ♦rt♠q ♦♥ D st ♥

DerX(logD)♦♥♥①♦♥ ♥s F .

♥s st ♦rr t♦t ♦♥♥①♦♥ ♦rt♠q ∇ sr F sr ♥♦té K∇.

♦t ∇ ♥ ♦♥♥①♦♥ ♦rt♠q sr F (Ui)1≤i≤n ♥ r♦r♠♥t à s ♦

rts X. ♦t s0 ∈ H0(Ui,F) t q 0 /∈ s0(Ui). ①st σ ∈ H0(Ui,Ω1X(logD))

t q ∇s0 = σ ⊗ s0, ♦rs K∇ = dσ.

♠♠ ♦t F ♥ ré ♥ r♦t ♦♠♣① sr X t ♥ ♦♥♥①♦♥ ♦

rt♠q sr F ♦rs ♣♦r t♦t ♦r♠ r♠é τ ∈ H0(X,Ω1

X(logD)), +τ⊗id

st ♥ ♦♥♥①♦♥ ♦rt♠q sr F ♦rr K = K.

Pr ♣♣♦s♦♥s q ∇ st é♥ ♣r (s) = σ⊗ s ♣♦r t♦t st♦♥ ♥♦♥ ♥

s F

♦rs(∇+ τ ⊗ id)(s) = ∇(s) + τ ⊗ s

= σ ⊗ s+ τ ⊗ s

= (σ + τ)⊗ s

Page 102: Structures de Poisson logarithmiques: invariants

♣tr Préq♥tt♦♥ s strtrs P♦ss♦♥

♦rt♠qs

t(∇+ τ ⊗ id)(fs) = ∇(fs) + τ ⊗ id(fs)

= df ⊗ s+ fσ ⊗ s+ fτ ⊗ s

= df ⊗ s+ f(∇+ τ ⊗ id)s.

D st ♥ sr à r♦s♠♥ts ♥♦r♠① ♦rs ①st ♥ s②stè♠ ♦♦r♦♥♥és

(zi)1≤i≤n X ♥ t♦t ♣♦♥t p D t q

σ =r∑

i=1

aidzi

zi+

n∑

i=r+1

aidzi

♦ù ai ∈ H0(X,OX).

♠♠ ♦♥t D ♥ sr à r♦s♠♥ts ♥♦r♠① t α ∈H0(X,Ω1

X(logD)) dα = 0 ♦rs rés α st ♦♥st♥t sr t♦t

♦♠♣♦s♥t ♣rt s♥èr D. ♥ s ♦r♠s ②♥t ♠♦♥s ♥

rés ♥♦♥ ♥ ♠t r♣rés♥tt♦♥ s♥t

α =r∑

j=1

αidfjfj, α1, ..., αr ∈ C.

♠♠ ♥♦s é♠♦♥tr♦♥s ♣r♦♣♦st♦♥ s♥t

Pr♦♣♦st♦♥ ♦t D ♥ sr à r♦s♠♥ts ♥♦r♠① X t ♥ ♦♥

♥①♦♥ à ♣ôs ♦rt♠qs ♦♥ D F . ♦rr K∇ st ♥ s

t s♠♥t s ♦r♠ ♦♥♥①♦♥ ss♦é st ♦r♠ σ =r∑i=1aidzi

zi

ai ∈ C.

rt♦♥ ♠♦♥tr q t♦t ♦♥♥①♦♥ ∇ sr F , ♦rt♠q ♦♥ D

ér rt♦♥ s♥t

∇δ(fs)− f∇δs = δ(f)s

♣♦r t♦s s ∈ M, f ∈ OX t δ ∈ DerX(logD).

♥ s♣♣♦s q h st ♦♥t♦♥ é♥t♦♥ D t ♦♥ r♣♣ q♥ ♦♣ér

tr ér♥t ϕ ♦rr r sr F st t ♦rt♠q ♦♥ D s s 7→[ϕ(hs) − hϕ(s)]h−1 st ♥ ♦♣értr ér♥t ♦rr (r − 1) sr F . ♥ ♥♦t

+1 (logD) ♠♦ s ♦♣értrs ér♥ts ♦rr ≤ 1, ♦rt♠qs

♦♥ D sr F .P♦r t♦t ♦♥♥①♦♥ ♦rt♠q ∇ t t♦t δ ∈ DerX(logD) ♦♥ ∇δ ∈+

1 (logD).

♠♠ ♦t ϕ ♥ ♦♣értr ér♥t ♦rt♠q ♣r♠r ♦rr P♦r

t♦t f ∈ OX , ①st ♥ ♥q f ∈ OX t q [ϕ(fs)− fϕ(s)] = f s.

Page 103: Structures de Poisson logarithmiques: invariants

Préq♥tt♦♥ s strtrs ♦s②♠♣tqs

Pr P♦r t♦t ♦♣értr ér♥t ♦rt♠q ♣r♠r ♦rr ϕ, [s 7→ϕ(fs)− fϕ(s)] ∈ +

0 (logD). ①st f ∈ OX t q [ϕ(fs)− fϕ(s)] = f s. g

st ♥ tr éé♠♥t OX t q [ϕ(fs) − fϕ(s)] = gs, ♦rs f s = gs ♣♦r t♦t

s ∈ E ♦♥ f = g.

♦r♦r ϕ st ♥ ♦♣értr ér♥t ♦rt♠q ♣r♠r ♦rr

♦♥ D ♦rs h ∈ hOX

Pr P♦r t♦s s ∈ F , ϕ(hs)− hϕ(s) = hs t ①st g ∈ OX t q ϕ(hs)−hϕ(s) = hgs Pr st (h− hg)s = 0 ♣♦r t♦t s.

s♥st q t♦t ♦♣értr ér♥t ϕ ♦rt♠q ♣r♠r ♦rr ♦♥

D, ♦♥♥ à ♥ ♣♣t♦♥ σϕ : OX → OX é♥ ♣r σϕ(f) = f t q

[ϕ(fs)− fϕ(s)] = f s ♣♦r t♦t s ∈ F .

♠♠ P♦r t♦t ϕ ∈ +1 (logD), σϕ ∈ H0(X,Der1X(logD))

Pr ♦♥t f, g ∈ OX t s ∈ F . ♥

σϕ(f.g)s = ϕ(f(gs)− fgϕ(s)

= σϕ(f)(gs) + fϕ(gs)− fgϕ(s)

= σϕ(f)(gs) + f(ϕ(gs)− gϕ(s))

= (σϕ(f)g + fσϕ(g))s

tr ♣rtσϕ(h)s = ϕ(hs)− hϕ(s)

= hmh(s)

♦♥ (σϕ(h)− hmh)s = 0 ♣♦r t♦t s.

Pr st σϕ(h) ∈ hOX σϕ ∈ H0(X,Der1X(logD)).

Pr♦♣♦st♦♥ +1 (logD) st st ♣♦r ♦♠♠ttr

Pr ♦t ϕ1, ϕ2 ① éé♠♥ts +1 (logD) ♥

ϕ1ϕ2(fs) = ϕ1

(fϕ2(s) + f2s

)

= fϕ1(fϕ2(s) + ϕ1(f2s))

= fϕ1 (ϕ2(s)) + f1ϕ2(s) + f2ϕ1(s) +¯f2

1.s

ç♦♥ ♥♦

ϕ2ϕ1(fs) = fϕ2 (ϕ1(s)) + f2ϕ1(s) + f1ϕ2(s) +¯f1

2s

♣r st

ϕ1ϕ2(fs)− ϕ2ϕ1(fs)− f (ϕ1ϕ2 − ϕ2ϕ1) (s) = ( ¯f21 − ¯f1

2)s.

Pr rs ♣♦r t♦t ϕ1, ϕ2 ∈ +1 (logD), ①st h1, h2 ∈ OX ts q

[ϕ2(hs)− hϕ2(s)]1h = h2s t [ϕ1(hs)− hϕ1(s)]

1h = h1s

h2 = hh2 t h1 = hh1.

♠ê♠ ①st h21, h12 ∈ OX ts q ¯h12= hh12 t ¯h2

1= hh21.

Pr st

ϕ1ϕ2(hs)− ϕ2ϕ1(hs)− h (ϕ1ϕ2 − ϕ2ϕ1) (s) = (¯h21 − ¯h1

2)s = h[h21 − h12]s

Page 104: Structures de Poisson logarithmiques: invariants

♣tr Préq♥tt♦♥ s strtrs P♦ss♦♥

♦rt♠qs

♥trté s ♦r♠s ♦rt♠qs r♠és

♦t X ♥ rété ♦♠♣① ♠♥s♦♥ 2n D ♥ sr rét X.

♠♠ D stst ♣r♦♣rété érè♠ ♦rs ♣♦r t♦t

ω ∈ Ω2X(logD), ♦♥ res(ω) ∈ ΩX .

Pr é♦ éq♥ s ♣r♦♣rétés t té♦rè♠

♥s st ♥♦s s♣♣♦s♦♥s q D stst ♣r♦♣rété té♦rè♠

és♥♦♥s ♣r HkDR−Log(X) kime r♦♣ ♦♦♠♦♦ ♠ ♦rt

♠q X. ♦s ♦♥s st ♠♦r♣s♠s r♦♣s s♥t

... // H∗(X,Z)i // H∗(X,C)

∼=

p // H∗(X,Ω∗X(logD)) // ...

H∗(X,Ω∗X)

♦t [ω] ♥ éé♠♥t H2(X,Ω∗X(logD))

é♥t♦♥ ω st t ♥tér s [ω] ♣♣rt♥t à ♠ p i. ♣r♦♣♦st♦♥ s♥t ♥♦s ♦♥♥ ♥ rtérst♦♥ s ♦r♠s ♦rt♠qs

r♠és

Pr♦♣♦st♦♥ ♦t ω ♥ st♦♥ Ω2X(logD). ♥

d(ω) = 0 s t s♠♥t s s ♦r♠ rés t s ♣rt ss s♦♥t t♦ts r♠és

Pr ♥t t q D ér s ♣r♦♣rétés é♦rè♠ t

♦♥ ω =dh

h∧ res(ω) + ωl ♦ù res(ω) st ♦r♠ rés ss♦é à ω t ωl st

♣rt ss ω.

é♦rè♠ ♦t ω ♥ ♦r♠ r♠é ♦rt♠q ♦♥

s ♣r♦♣rétés s♥ts s♦♥t éq♥ts

ω =dh

h∧ ψ + η st ♥tér

res(ω) st ①t t ①st [ω0] ∈ H2(X,C) ♥tér t q

[ω0] = [η].

Pr ω st ♥tér ♦rs ①st [ω1] ∈ H2(X,Z) t q [ω] = p i[ω1].

♦♥tr♦♥s q [ω0] = i([ω1]).

Psq ω st ♥tér ①st [ω1] ∈ H2(X,Z) t q [ω] = p i[ω1]. tr♠♥t

t ①st ♥ ♦r♠ ♦rt♠q α = α0dh

h+ α1 t q ω− ω0 = dα. ♦♥

−dα0 = ψ t η = ω0 + dα1.

é♣r♦q♠♥t s ω0 + dλ = η t ψ = dβ ω0 ♥tr ♦rs

ω = d(−β dhh) + η

= ω0 + dλ+ d(−β dhh)

= ω0 + d(λ− βdh

h)

Page 105: Structures de Poisson logarithmiques: invariants

Préq♥tt♦♥ s strtrs ♦s②♠♣tqs

Pr st [ω] = [η] = [ω0].

s tr① ♦st♥t ♥s ❬♦st♥t ❪ t ♦r ♥s ❬♦r ❪ r

♣♦s♥t sr ♣r♥♣ q♥tt♦♥ ♣r♦♣♦sé ♣r r ♥s ❬r ❪

♣r♥♣ ♣r♠t ♠♦ésr ♠té♠tq♠♥t q s ♣②s♥s ♣♣♥t

q♥tt♦♥ st sé sr ♦♥strt♦♥ ♥ s♦♠♦r♣s♠ ♥tr èr

s ♦♣értrs sr ♥ s♣ rt H t èr s ♦srs s

sqs F(X) ♦♥sttés s ♦♥t♦♥s é♥s ♥s ♥ rété s②♠♣tq (X,ω).

Ps ♣résé♠♥t s ϕ st ♥ t s♦♠♦r♣s♠ rt stsr s ♣r♦♣rétés

s♥ts

ϕ st t

s f st ♥ ♦sr ♦♥st♥t ♦rs ϕ(f) st ♠t♣t♦♥ ♣r f.

[f1, f2] = f3 ♦rs ϕ(f1)ϕ(f2) − ϕ(f2)ϕ(f1) = −ihϕ(f3) ♦ù h és♥ ♦♥

st♥t P♥

q éqt à ①st♥ ♥ r♣rés♥tt♦♥ ϕ (F(X), ω) r♥♥t ♦♠♠

tt r♠♠ èrs ♥rt s♥t

0 // F(X)m // +

1 (Γ(L))σ // DerX // 0

0 // R //

OO

(F(X), ω)

ϕ

OO

// Ham(F(X))

OO

// 0

ϕ é♥ ♣r

ϕ(as) = ∇v(a)s+ 2iπas

♦r ❬❯r♥ ❪ ♦ù ∇ st ♥ ♦♥♥①♦♥ ♥s ♥ ré ♥ r♦t ♦♠♣① L sr

X t Ham(F(X)) st èr s ♠♣s ♦♠♥t ♠t♦♥♥s

♦rsq ♦♥ r♠♣ rété s②♠♣tq (X,ω) ♣r ♥ rété ♦s②♠♣tq

(X,ω,D), ①è♠ ♥ r♠♠ st r♠♣é ♣r

0 // C // (OX , ω) // HωX(OX) // 0

♥♦s ♠♥t♥♦♥s ①♣rss♦♥ ϕ ♦♥♥é ♣r ♦rs ♣♦r t♦s f, g ∈H0(X,OX) t s ∈ E , ♦♥

ϕ(f)ϕ(g)s = ϕ(f)(ϕ(g)s)

= ϕ(f)[∇v(g)s+ 2πigs]

= ∇v(f)(∇v(g)s+ 2πigs) + 2πi(f∇v(g)s+ 2πifgs)

= ∇v(f)∇v(g)s+ 2πi∇v(f)(gs) + 2πi∇v(g)s− 4π2fgs

= ∇v(f)∇v(g)s+ 2πi(H(df).g)s+ 2πig∇v(f)s+ 2πif∇v(g)s− 4π2fg

♥ é♥♥t s rôs f t g ♦♥ ♦t♥t

ϕ(g)ϕ(f)s = ∇v(g)∇v(f)s+ 2πi(H(dg).f)s+ 2πig∇v(g)s+ 2πig∇v(f)s− 4π2gfs

♣r st

[ϕ(f), ϕ(g)]s = [∇v(f),∇v(g)]s+ 4πiω(v(f), v(g))s

Page 106: Structures de Poisson logarithmiques: invariants

♣tr Préq♥tt♦♥ s strtrs P♦ss♦♥

♦rt♠qs

tr ♣rt

ϕ(f, g) = ∇v(f,g)s+ 2πif, gs= ∇[v(f),v(g)]s+ 2πif, gs= [∇v(f),∇v(g)]−K∇(v(f), v(g))s+ 2πif, gs= [ϕ(f), ϕ(g)]s+ 2πif, gs−K∇(v(f), v(g))s

♥s s ♣r♦♣rété ♣r♥♣ r st stst s t s♠♥t s

K∇ = 2πiω

♥ ♥s ♣r♦é ♣r♦♣♦st♦♥ s♥t

Pr♦♣♦st♦♥ ❯♥ rété ♦s②♠♣tq (X,ω,D) st ♣réq♥t s t

s♠♥t s ①st ♥ ré ♥ r♦t ♦♠♣① sr X ♣♦ssé♥t ♥ ♦♥♥①♦♥

♦rt♠q ♦♥ D ♦rr 2iπω.

Préq♥tt♦♥ s strtrs P♦ss♦♥ ♦rt

♠qs

♥s tt ♣rt (X,D,Υ) és♥r ♥ rété P♦ss♦♥ ♦rt♠q

♦♥ ♥ sr rét t r D X t♥sr P♦ss♦♥ ss♦é Υ.

qs r♠rqs sr ♦♦♠♦♦ s rétés P♦ss♦♥ ♦rt♠qs

♥ ♥♦t ∂D ér♥t P♦ss♦♥ ♦rt♠q Υ. ss ♦♦

♠♦♦ P♦ss♦♥ ♦rt♠q ♥ ♦② P sr ♥♦té [P ]D.

é♥t♦♥ ∂D t ér♥t d ♠ ♦rt♠q ♦♥

♠♠ s♥t

♠♠ ♣♣t♦♥ H ér

∂D H = −H d

♥ ♥ ét ♣r♦♣♦st♦♥ s♥t

Pr♦♣♦st♦♥ H∗DR−Log(X) st r♦♣ ♦♦♠♦♦ ♠ ♦

rt♠q X ♦rs H : (Ω∗X(logD), d) → (Der∗X(logD), ∂log) ♥t ♥ ♠♦r

♣s♠ é♥ ♣r

H : H∗DR−Log(X) → H∗

PS(X)

[α] 7→ [H(α)]D

Page 107: Structures de Poisson logarithmiques: invariants

Préq♥tt♦♥ s strtrs P♦ss♦♥ ♦rt♠qs

ss r♥P♦ss♦♥ ♦rt♠q

♦t (X,D,Υ) ♥ rété P♦ss♦♥ ♦rt♠q p : L → X ♥ ré ♥

r♦t ♦♠♣① sr X t Γ(L) s♦♥ ♠♦ st♦♥s

é♥t♦♥ ❯♥ ért♦♥ ♦rt♠q ♦♥trr♥t Dlog sr p : L → X

st ♥ ♣♣t♦♥ Dlog : C♥ér Ω1X(logD) → EndC(Γ(L)) t q

Dlogα (fs) = fDlog

α s+ (H(α)f)s

♣♦r t♦t α ∈ Ω1X(logD) t s ♥ st♦♥ ♦ Γ(L).

Dlog st t ♦♠♣t ♥ ♠étrq r♠t♥♥ h sr p : L→ X s ♣♦r t♦t

α ∈ ΩX(logD), s1, s2 ∈ Γ(L)

H(α)(h(s1, s2)) = h(Dlogα s1, s2) + h(s1, D

logα s2).

♠rq ∇ st ♥ ♦♥♥①♦♥ ♦rt♠q sr p : L → X ♦rs

Dα = ∇H(α) st ♥ ért♦♥ ♦rt♠q ♦♥trr♥t sr p : L→ X

é♥t♦♥ ♥ ♣♣ ♦rr ♥ ért♦♥ ♦rt♠q ♦♥trr♥t

Dlog sr p : L→ X t♦t ♣♣t♦♥

CD : Ω1X(logD)× Ω1

X(logD) → EndC(Γ(L))

é♥ ♣r

CD(α, β) = Dlogα Dlog

β −Dlogβ Dlog

α −Dlogα,β

♣♦r t♦s α, β ∈ Ω1X(logD).

♥ ♣r♦♣rété s♥t s ért♦♥s ♦rt♠qs ♦♥trr♥ts

Pr♦♣♦st♦♥ CD st OX♥ér ♥ts②♠étrq

Pr P♦r t♦s α, β ∈ Ω1X(logD) ♦♥

CD(β, α)s = (Dlogβ Dlog

α −Dlogα Dlog

β −Dlogβ,α)s

= −(Dlogα Dlog

β −Dlogβ Dlog

α −Dlogα,β)s

= −CD(α, β).

♦t f ♥ st♦♥ OX . ♥

CD(fα, β)s

= (Dlogfα Dlog

β −Dlogβ Dlog

fα −Dlogfα,β)s

= fDlogα Dlog

β s−Dlogβ (fDαs)−Dlog

fα,β+(H(β)f)αs

= fDlogα Dlog

β s− fDlogβ (Dαs)− (H(β)f)Dlog

α s− fDlogα,βs+ (H(β)f)Dlog

α s

= f(Dlogfα Dlog

β −Dlogβ Dlog

fα −Dlogfα,β)s

= fCD(α, β)s.

Page 108: Structures de Poisson logarithmiques: invariants

♣tr Préq♥tt♦♥ s strtrs P♦ss♦♥

♦rt♠qs

Pr♦♣♦st♦♥ ♦t p : L→ X ♥ ré ♥ r♦t ♦♠♣① sr (X,D,Υ) ♠♥

♥ ért♦♥ ♦rt♠q ♦♥trr♥t Dlog ♦rr CD. ♦rs

CD é♥t ♥ ss ♦♦♠♦♦ [CD]D ♥s H2

PS(X),

[CD]D ♥ é♣♥ ♣s Dlog,

♣s Dlog st ♦♠♣t ♠étrq r♠t♥♥ h sr p : L →X ♦rs CD = −CD.

Pr ♦t s ♥ st♦♥ p : L → X ♥ s♥♥♥t ♣s sr X. Psq

q r p : L → X st ♥♠♥s♦♥♥ ♦rs té ♥tr Ω1X(logD)

t Der1X(logD)) ♠♣q q ♣♣t♦♥ α 7→ Dαss st C♥ér ①st ♦♥

♥ ♥q ♠♣ trs ♦rt♠q δ sr X t q

Dlogα s = 〈α, δ〉s

♦ù 〈−,−〉 és♥ r♦t té ♥tr (Ω1X(logD) t Der1X(logD)).

♣s ♣♦r t♦s α, β ∈ ΩX(logD) ♦♥

CDlog(α, β)s = (Dlogα Dlog

β −Dlogβ Dlog

α −Dlogα,β)s

= Dlogα (〈β, δ〉s)−Dlog

β (〈α, δ〉s)− 〈α, β, δ〉s= 〈α, δ〉〈β, δ〉s+ H(〈α, δ〉)s− 〈β, δ〉〈α, δ〉s− H(〈β, δ〉)s− 〈α, β, δ〉s= H(α)(〈β, δ〉)s− H(β)(〈α, δ〉)s− 〈α, β, δ〉s= ∂Dδ(α, β)s

♦♥ CDlog = ∂Dδ. t ♣r st ∂DCDlog = ∂2Dδ = 0 ♦♥ CD st ♥ ♦②

P♦ss♦♥ ♦rt♠q

♦t D′ ♥ tr ért♦♥ ♦rt♠q ♦♥trr♥t sr p : L → X

♦rr ss♦é C ′D t δ′ ♠♣ trs ♦rt♠q ss♦é

♥ CD′ − CDlog = ∂Dδ′ − ∂Dδ CD′ = CDlog + ∂D(δ

′ − δ).

Pr rs ♣♦r t♦t α ∈ Ω1X(logD) ♦♥ D′

α −Dα ∈ EndC(Γ(L))

①st ♦♥ ♥ ♠♣ trs ♦rt♠q δ′′ t q ♣♦r t♦t s ∈ Γ(L)

(D′α −Dlog

α )s = 〈α, δ′′〉s♦♥ 〈α, δ”〉s = D′

αs−Dlogα s = 〈α, δ′〉−〈α, δ〉s 〈α, δ”〉 = 〈α, δ′−δ〉 δ′′ = δ′−δ

t ♦♥ CD′ = CDlog +∂D(δ′− δ) = CDlog +∂Dδ” stàr [CD′ ]log = [CDlog ]log.

♣♣♦s♦♥s q Dlog st ♦♠♣t ♥ ♠étrq r♠t♥♥ h sr p :

L→ X t s♦t (e) ♥ s ♦rt♦♦♥ ♦ Γ(L) ♦rs α ∈ Ω1X(logD).

♥ ♦♥

H(α)(h(e, e)) = h(Dlogα e, e) + h(e,Dlog

α e) 0 = h(〈α, δ〉e, e) + h(e, 〈α, δ〉e)

〈α, δ〉 + 〈α, δ〉 = 0 δ + δ = 0. s♥st q δ t ♦♥ CDlog = ∂Dδ s♦♥t

♠♥rs ♣rs

♣rt ♣r♦♣rété iii) té♦rè♠ s♥st q 12πi [CDlog ]D ∈ H2

PS(X)

♥ ♥ ét é♥t♦♥ s♥t

é♥t♦♥ 12πi [CDlog ]D st ♣r♠èr ss r♥P♦ss♦♥ ♦rt♠q

p : L→ X.

Page 109: Structures de Poisson logarithmiques: invariants

Préq♥tt♦♥ s strtrs P♦ss♦♥ ♦rt♠qs

♦s ♦♥s à ♣rés♥t étr ♥ ♥ ♥tr ♣r♠èr ss r♥ C1(L) ♥

ré ♥ r♦t ♦♠♣① r♠t♥ p : L → X sr ♥ rété P♦ss♦♥ ♦

rt♠q (X,D,Υ) t s ss r♥P♦ss♦♥ ♦rt♠q 12πi [CDlog ]D. ♦s

s♣♣♦s♦♥s q♥ ♣s D stst s ♣r♦♣rétés s♥ts

D st à r♦s♠♥t ♥♦r♠①

D = ∪j∈IDj é♦♠♣♦st♦♥ ♥ ♦♠♣♦s♥ts rréts D, ♦rs

q Dj st ss I és♥ ♥s♠ s ♥s

♦t ∇ ♥ ♦♥♥①♦♥ ♦rt♠q sr ♥ ré ♥ r♦t ♦♠♣① r♠t♥ L sr

X. ♦r♠ ♦♥♥①♦♥ ♦rt♠q α0 é♥ ♣r rt♦♥ ∇δs = 〈α0, δ〉sér dα0 = K.

♥ ♦♥

c1(L) = [i

2πK]D = [

i

2πdα0].

♥ ♣♦s ♣♦r t♦t α ∈ Ω1X(logD) Dα := ∇H(α).

♦t δ ♥ ♠♣ trs ♦rt♠q é♥ ♣r rt♦♥ ♥

Dαs = ∇H(α)s⇔ 〈α, δ〉s = 〈α0, H(α)〉s⇔ 〈α, δ〉s = −〈α, H(α0)〉 ⇔ δ = −H(α0).

Pr st CDlog = ∂Dδ = −∂DH(α0) = H(dα0).

♥ ♦♥ [i

2πCDlog ]D = [

i

2πH(dα0)] = H([

i

2π]dα0) = H(c1(L)).

tr♠♥t t s sss r♥P♦ss♦♥ ♦rt♠q t r♥ ré

♥ r♦t ♦♠♣① r♠t♥ L s♦♥t és ♣r rt♦♥

[i

2πCDlog ]D = H(c1(L)).

♦t p : L → X ♥ ré ♥ r♦t ♦♠♣① r♠t♥ ♠♥ ♥ ért♦♥ ♦♥

trr♥t ♦rt♠q Dlog ♦♥ ♥ sr D stss♥t s ②♣♦tèss

t sss ♣rès ♣r♥♣ r ♥s ❬r ❪ ♠♦r

♣s♠

ϕ : OX → EndC(Γ(L))

é♥ ♣r

ϕ(f)s = Dlogdf s+ 2πifs

♦t êtr ♥ r♣rés♥tt♦♥ èr (OX , −,−Υ) ♣r Γ(L). q ♠♣q q

CDlog = −2πiΥ

♥ ♥ ét q

Pr♦♣♦st♦♥ ♦♣értr ϕ st ♥ ♦♠♦♠♦r♣s♠ èrs s t

s♠♥t s CDlog = −2πiΥ

♦s ♦♣t♦♥s é♥t♦♥ s♥t

é♥t♦♥ ❯♥ rété P♦ss♦♥ ♦rt♠q (X,D,Υ) st t ♦ ♣réq♥

t s ①st ♥ ré ♥ r♦t ♦♠♣① r♠t♥ p : L → X ♣♦r q

♦♣értr ϕ é♥ ♣r st ♥ é♥ t st ♥ ♠♦r♣s♠ èrs

Page 110: Structures de Poisson logarithmiques: invariants

♣tr Préq♥tt♦♥ s strtrs P♦ss♦♥

♦rt♠qs

Pr♦♣♦st♦♥ ♦t (X,D,Υ) ♥ rété P♦ss♦♥ ♦rt♠q ♦♥

♥ sr D stss♥t s ②♣♦tèss t (X,D,Υ) st ♦ ♣réq♥

t s ①st ♥ ♠♣ trs ♦rt♠q δ t ♥ ♦r♠ ♦rt♠q

ω ♥tér t q

Υ+ ∂Dδ = H(ω).

Pr ♣♣♦s♦♥s (X,D,Υ) ♦ ♣réq♥t t ♥♦t♦♥s CDlog ♦rr

ért♦♥ ♦♥trr♥t Dlog ss♦é ré ♣réq♥tq L→ X ♦rrs♣♦♥♥t

♦rsi

2πCDlog = Υ ♦t K∇ ♦rr ♦♥♥①♦♥ r♠t♥♥ ∇ sr L.

♣rès ♦♥ c1(L) = [i

2πK∇]. ♥ ♣r♥ ω =

i

2πK∇ Pr rs ∇ ♥t

♥ ért♦♥ ♦rt♠q ♦♥trr♥t D é♥ ♣r Dα = ∇H(α) ♣♦r t♦t

α ∈ Ω1X(logD). ♥ ♥♦t CD s ♦rr ♣rès rt♦♥ ♦♥

H([ω]) = [i

2πCD]

r à éqt à [H(ω)] = [i

2πCD]

D. ♥ rt Pr♦♣♦st♦♥ ♦♥ ♥

ét q [CDlog ]D = [CD]D. q ♠♣q q ①st ♥ ♠♣ trs

♦rt♠q λ t qi

2πCDlog =

i

2π∂Dλ+

i

2πCD =

i

2π∂logλ+ H(ω). stàr

Υ+ ∂log(−i

2πλ) = H(ω). st ♦♥ ♣r♥r δ = − i

2πλ.

é♣r♦q♠♥t ♦♥ s♣♣♦s qs ①st♥t δ t ω ♦♠♠ ♥s s ②♣♦tèss

Pr♦♣♦st♦♥ ♦rs ♥ rt ♥térté ω ♥ ré ♥ r♦t ♦♠♣①

r♠t♥ L → X ♥ ♦♥♥①♦♥ r♠t♥♥ ♦rt♠q ∇ t ♦rr

−2πω. P♦s♦♥s Dlog(α)s = ∇H(α)s+ 2πi〈δ, α〉 t ♠♦♥tr♦♥s q st ♥ ért♦♥

♦♥trr♥t ♦rt♠q ♦♥t ♦rr CDlog Dlog ér rt♦♥

st r q st ♥ ért♦♥ ♦♥trr♥t ♦rt♠q

♦♥t α, β ∈ Ω1X(logD) t s ♥ st♦♥ L. ♥

CDlog(α, β)s = (Dlogα Dlog

β −Dlogβ Dlog

α −Dlog[α,β])s

= Dlogα (∇H(β)s+ 2πi〈β, δ〉)s−Dlog

β (∇H(α)s+ 2πi〈α, δ〉s)− ∇H[α,β]s− 2πi〈[α, β], δ〉s= ∇H(α)((∇H(β)s+ 2πi〈β, δ〉)s) + 2πi〈α, δ〉((∇H(β)s+ 2πi〈β, δ〉)s)− ∇H(β)((∇H(α)s+ 2πi〈α, δ〉)s)− 2πi〈β, δ〉((∇H(α)s+ 2πi〈α, δ〉)s)− ∇[H(α),H(β)]s− 2πi〈[α, β], δ〉s=

(∇H(α)∇H(β)s−∇H(β)∇H(α)s−∇[H(α),H(β)]s

)

+ 2πi(H(α)〈β, δ〉)s− H(β)〈α, δ〉)s− 〈[α, β], δ〉s

)

= −2πi (ω) (H(α), H(β))s+ 2πi∂Dδ (α, β) s

= −2πiΥ(α, β)s

♣♦r α, β ∈ Ω1X(logD) t ♣♦r t♦t st♦♥ ♦ s L.

P♦s♦♥s h = h1...hk é♦♠♣♦st♦♥ h ♥ ♦♠♣♦s♥ts rréts Di D

Page 111: Structures de Poisson logarithmiques: invariants

①♠♣s ♣♣t♦♥s

é♥s ♣r s hi. ♣rès Pr♦♣♦st♦♥ s ♦r♠s ♦rt♠qs ♥té

rs s♦♥t à réss ①ts t à ♦r♠ ♦♦♠♦r♣ ss♦é r♠é t ♥tér

ω st ♥tér ♦rs H(ω) =k∑i=1

Ri

hi(H(dhi)) +H(ω0) R

i st♦♥ ♦ OX

t ω0 ♥ ♦r♠ ♦♦♠♦r♣ ♥tér ♥ ♥ ét ♦r♦r s♥t

♦r♦r ♦t (X,D,Υ) ♥ rété P♦ss♦♥ ♦rt♠q ♦♥ ♥

sr D stss♥t s ②♣♦tèss é♦rè♠ (X,D,Υ) st ♦

♣réq♥t s ①st ♥ ♠♣ trs ♦rt♠q δ s ♦♥t♦♥s ♦♦

♠♦r♣s Ri, i = 1, ..., k t ♥ ♦r♠ ω0 ♦♦♠♦r♣ sr ♥ s♦s rété

♠♥s♦♥ ♥ X, ♥tér t q

Υ+ ∂D(δ −k∑

i=1

Ri

hi(H(dhi))) = H(ω0)

①♠♣s ♣♣t♦♥s

Préq♥tt♦♥ (C2, π = z1∂z1 ∧ ∂z2)

P♦s♦♥s X = C2;D = (0, z), z ∈ C ♦s s♦♥s q ω0 = dz1 ∧ dz2 st ♥

strtr s②♠♣tq sr C2 ♦♥t strtr P♦ss♦♥ ss♦é st é♥ ♣r

z1, z2 = 1 ♥ ♣♦s♥t f, gnew := f, h1g, h2 − f, h2g, h1 ♦ù h1 = z1 t

h2 = z1z2 ♦♥ ♦t♥t z1, z2new = z1 q st ♥♦tr strtr P♦ss♦♥ π.♦♥tr♦♥s

q tt strtr st ♦ ♣réq♥t P♦r ♦s ♦♥s rr ♥

st♦♥ ω0 Ω2X(logD) t q

①st ♥ st♦♥ α0 ∈ Ω2X ♥tér t α0 ∈ [ω0]

H(ω0) ∈ [z1∂z1 ∧ ∂z2 ]♦♥sér♦♥s ♦♥ ♦♠♣① ♠ ♦rt♠q s♥t

K : 0 // ΩA(log I)X d0 // Ω1X(logD)2

d1 // ΩA(log I)X // 0

♦ù d0(f) := z1∂z1fdz1z1

+ ∂z2fdz2 t d1(f1dz1z1

+ f2dz2) = (z1∂z1f2 − ∂z2f1)dz1z1

∧ dz2♦rs H2(K) = 0 ♥ t ♣♦r t♦t st♦♥ g Ω1

X(logD) ①st ♥ st♦♥

f OX t q d1(fdz2) = gdz1z1

∧ dz2. s♥st q t♦t st♦♥ Ω1

X(logD) sr s♦t♦♥ ♣r♦è♠ st

♣r♥r α0 = 0.

Préqtt♦♥ CP1 ♠♥ strtr

♥s ❬♦r♦s♥ t ❪ st é♠♦♥tré q s strtrs P♦ss♦♥

②♥♥r♥ t r♦♦♥st♥t♦r s♦♥t ♦♠♣ts

sr CP1. tr♠♥t t r ♦♠♥s♦♥ ♥ér ♥t é♠♥t ♥ strtr

Page 112: Structures de Poisson logarithmiques: invariants

♣tr Préq♥tt♦♥ s strtrs P♦ss♦♥

♦rt♠qs

P♦ss♦♥ sr CP1 ♥s ❬♦r♦s♥ t ❪ t ❬♦t♦ ❪ s trs ♠♦♥

tr♥t q tt strtr st ♣r♠étré sr C ♣r

πλ := − i

2(zz + 1)(λ+ (λ+ 2)zz))

∂z∧ ∂

∂z.

t q st s♥èr ♣♦r λ ∈ [−2, 0]

♦t♦ ♠♦♥tr é♠♥t ♥s ❬♦t♦ ❪ q s r♦♣s ♦♦♠♦♦ P♦s

s♦♥ tt strtr s♦♥t

H0 ∼= H1 ∼= C; H2 ∼= C2

t s λ = 0.

P♦r λ = 0 ♦♥

π0 = −i(zz + 1)z∂

∂z∧ z ∂

∂z

♦ù

z∂z :=z

2(∂x − i∂y); t z∂z :=

z

2(∂x + i∂y).

P♦r t♦ts ♦♥t♦♥s a, b ♦♥

a, b = −i(1 + zz)zz(∂a

∂z

∂b

∂z− ∂b

∂z

∂a

∂z).

st ♥ ♦rt♠q ♦♥ sr D0 := zz = 0.P♦r t♦t ♦♥t♦♥ a, ♦♥

∂0f =∂a

∂zz,− − ∂a

∂z−, z

= i(1 + zz)(z∂a

∂zz∂

∂z− z

∂a

∂zz∂

∂z).

éqt♦♥ ♦♥ ét q H0 ∼= C.

♠ê♠ ♣♦r t♦t ♠♣ trs ♦rt♠q δ = az∂

∂z+ bz

∂z♦♥

∂1δ = i(1 + zz)(z∂za− z∂zb) + izz(a+ b).

Pr rs tt strtr ♥t sr X −D0 strtr s②♠♣tq é♥ ♣r

ω0 = i1

1 + zz

dz

z∧ dz

z.

♣s ♣♦r t♦ts ♦♥t♦♥s a, b ♦♥

(1 + zz)(z∂z(a)− z∂z(b)) 6= 1.

♥ t s ①st a0, b0 ts q (1 + zz)(z∂z(a0) − z∂z(b0)) = 1 ♦rs ♣♦r t♦t

z ∈ U := z ∈ C; 0 < |z| < 4 ♦♥ r za(0)− zb(0) =1

1 + zz. q st sr

r ♥tr♥rt q1

3=

1

4 ♦rsq♦♥ ♣r♥ z = 2 ♣s z = 3.

♠♦♥tr q ω0 6= 0 ∈ H2(CP1,Ω∗(logD0))

Page 113: Structures de Poisson logarithmiques: invariants

①♠♣s ♣♣t♦♥s

♥ ♣t ♦♥ ♦♥r q ω0 st ♥ strtr ♦s②♠♣tq sr CP1. Pr ♦♥

séq♥t H : Ω∗(logD0) → Der∗X(logD) st qss♦♠♦r♣s♠

t ♦♥

H2 ∼= H−1

(C[[z, z]]

〈1 + zz〉 i1

1 + zz

dz

z∧ dz

z

).

♠rq♦♥s q

H(i1

1 + zz

dz

z∧ dz

z) = −i(1 + zz)z∂z ∧ z∂z

s♥st q π0 st ♦ ♣réq♥t s t s♠♥t s

[i1

1 + zz

dz

z] = 0 ∈ H1((CP1,Ω∗(logD0)) ∼= C[[z]]

dz

z⊕ C[[z]]

dz

z.

q st sr ♦♥ π0 ♥st ♣s ♦ ♣réq♥t

Page 114: Structures de Poisson logarithmiques: invariants
Page 115: Structures de Poisson logarithmiques: invariants

♥♥①

P♦♥ts ét qqs

é♠♦♥strt♦♥s

é♠♦♥strt♦♥ ♦r♦r

♦t −,−0 ♥ strtr P♦ss♦♥ sr A = k[x, y] ♦ A = k[x1, x2, x3]

• s A = k[x, y].

♣rès ♠♠ st ♣r♦r q

a, a00b, c0 + b, a00c, a0 + c, a00a, b0 = 0

♣♦r t♦t a, b, c ∈ A.r ♣♦r t♦t f, g ∈ A,

f, g = (∂f

∂x

∂g

∂y− ∂f

∂y

∂g

∂x)x, y

♦♥

a, a00 = (∂a

∂x

∂a0∂y

− ∂a

∂y

∂a0∂x

)x, y0, b, c0 = (∂b

∂x

∂c

∂y− ∂b

∂y

∂c

∂x)x, y0

b, a00 = (∂b

∂x

∂a0∂y

− ∂b

∂y

∂a0∂x

)x, y0, c, a0 = (∂c

∂x

∂a

∂y− ∂c

∂y

∂a

∂x)x, y0

c, a00 = (∂c

∂x

∂a0∂y

− ∂c

∂y

∂a0∂x

)x, y0, a, b0 = (∂a

∂x

∂b

∂y− ∂a

∂y

∂b

∂x)x, y0

Page 116: Structures de Poisson logarithmiques: invariants

♥♥① P♦♥ts ét qqs é♠♦♥strt♦♥s

♦♥ ♥ ét q

1

(x, y0)2a, a00b, c0 + b, a00c, a0 + c, a00a, b0 =

∂a

∂x

∂a0∂y

∂b

∂x

∂c

∂y− ∂a

∂x

∂a0∂y

∂b

∂y

∂c

∂x− ∂a

∂y

∂a0∂x

∂b

∂x

∂c

∂y+∂a

∂y

∂a0∂x

∂b

∂y

∂c

∂x+

∂b

∂x

∂a0∂y

∂c

∂x

∂a

∂y− ∂b

∂x

∂a0∂y

∂c

∂y

∂a

∂x− ∂b

∂y

∂a0∂x

∂c

∂x

∂a

∂y+∂b

∂y

∂a0∂x

∂c

∂y

∂a

∂x+

∂c

∂x

∂a0∂y

∂a

∂x

∂b

∂y− ∂c

∂x

∂a0∂y

∂a

∂y

∂b

∂x− ∂c

∂y

∂a0∂x

∂a

∂x

∂b

∂y+∂c

∂y

∂a0∂x

∂a

∂y

∂b

∂x=

[∂a

∂x

∂a0∂y

∂b

∂x

∂c

∂y− ∂b

∂x

∂a0∂y

∂c

∂y

∂a

∂x] + [

∂a

∂x

∂a0∂y

∂b

∂y

∂c

∂x− ∂c

∂x

∂a0∂y

∂a

∂x

∂b

∂y] +

[∂a

∂y

∂a0∂x

∂b

∂x

∂c

∂y− ∂c

∂y

∂a0∂x

∂a

∂y

∂b

∂x] + [

∂a

∂y

∂a0∂x

∂b

∂y

∂c

∂x− ∂b

∂y

∂a0∂x

∂c

∂x

∂a

∂y] +

[∂b

∂x

∂a0∂y

∂c

∂x

∂a

∂y− ∂c

∂x

∂a0∂y

∂a

∂y

∂b

∂x] + [

∂b

∂y

∂a0∂x

∂c

∂y

∂a

∂x− ∂c

∂y

∂a0∂x

∂a

∂x

∂b

∂y]

= 0

• s A = k[x1, x2, x3]. P♦s♦♥s h := a0.

♦rs ♣♦r t♦t f, g, k ∈ A, ♦♥

f, h0 = (∂f

∂x1

∂h

∂x2− ∂f

∂x2

∂h

∂x1)x1, x20 + (

∂f

∂x1

∂h

∂x3− ∂f

∂x3

∂h

∂x1)x1, x30 +

(∂f

∂x2

∂h

∂x3− ∂f

∂x3

∂h

∂x2)x2, x30

g, k0 = (∂g

∂x1

∂k

∂x2− ∂g

∂x2

∂k

∂x1)x1, x20 + (

∂g

∂x1

∂k

∂x3− ∂g

∂x3

∂k

∂x1)x1, x30 +

(∂g

∂x2

∂k

∂x3− ∂g

∂x3

∂k

∂x2)x2, x30

f, h0g, k0 = (∂f

∂x1

∂h

∂x2− ∂f

∂x2

∂h

∂x1)(∂g

∂x1

∂k

∂x2− ∂g

∂x2

∂k

∂x1)(x1, x20)2

+(∂f

∂x1

∂h

∂x3− ∂f

∂x3

∂h

∂x1)(∂g

∂x1

∂k

∂x3− ∂g

∂x3

∂k

∂x1)(x1, x30)2+

(∂f

∂x2

∂h

∂x3− ∂f

∂x3

∂h

∂x2)(∂g

∂x2

∂k

∂x3− ∂g

∂x3

∂k

∂x2)(x2, x30)2

[(∂f

∂x1

∂h

∂x2− ∂f

∂x2

∂h

∂x1)(∂g

∂x1

∂k

∂x3− ∂g

∂x3

∂k

∂x1)+(

∂f

∂x1

∂h

∂x3− ∂f

∂x3

∂h

∂x1)(∂g

∂x1

∂k

∂x2−

∂g

∂x2

∂k

∂x1)](x1, x20)(x1, x30)

[(∂f

∂x1

∂h

∂x2− ∂f

∂x2

∂h

∂x1)(∂g

∂x2

∂k

∂x3− ∂g

∂x3

∂k

∂x2)+(

∂f

∂x2

∂h

∂x3− ∂f

∂x3

∂h

∂x2)(∂g

∂x1

∂k

∂x2−

∂g

∂x2

∂k

∂x1)](x1, x20)(x2, x30)+

[(∂f

∂x1

∂h

∂x3− ∂f

∂x3

∂h

∂x1)(∂g

∂x2

∂k

∂x3− ∂g

∂x3

∂k

∂x2)+(

∂g

∂x1

∂k

∂x3− ∂g

∂x3

∂k

∂x1)(∂f

∂x2

∂h

∂x3−

Page 117: Structures de Poisson logarithmiques: invariants

∂f

∂x3

∂h

∂x2)](x1, x30x2, x30)

♥ é♦♣♣♥t tt ①♣rss♦♥ ♦♥ ♦t♥t

♦♥t (x1, x20)2 st∂f

∂x1

∂h

∂x2

∂g

∂x1

∂k

∂x2− ∂f

∂x1

∂h

∂x2

∂g

∂x2

∂k

∂x1− ∂f

∂x2

∂h

∂x1

∂g

∂x1

∂k

∂x2+

∂f

∂x2

∂h

∂x1

∂g

∂x2

∂k

∂x1

♦é♥t (x1, x30)2 st∂f

∂x1

∂h

∂x3

∂g

∂x1

∂k

∂x3− ∂f

∂x1

∂h

∂x3

∂g

∂x3

∂k

∂x1− ∂f

∂x3

∂h

∂x1

∂g

∂x1

∂k

∂x3+

∂f

∂x3

∂h

∂x1

∂g

∂x3

∂k

∂x1

♦♥t (x2, x30)2 st∂f

∂x2

∂h

∂x3

∂g

∂x2

∂k

∂x3− ∂f

∂x2

∂h

∂x3

∂g

∂x3

∂k

∂x2− ∂f

∂x3

∂h

∂x2

∂g

∂x2

∂k

∂x3+

∂f

∂x3

∂h

∂x2

∂g

∂x3

∂k

∂x2

♦♥t x1, x2x1, x3 st∂f

∂x1

∂h

∂x3

∂g

∂x1

∂k

∂x2− ∂f

∂x1

∂h

∂x3

∂g

∂x2

∂k

∂x1− ∂f

∂x3

∂h

∂x1

∂g

∂x1

∂k

∂x2+∂f

∂x3

∂h

∂x1

∂g

∂x2

∂k

∂x1+

∂f

∂x1

∂h

∂x2

∂g

∂x1

∂k

∂x3− ∂f

∂x1

∂h

∂x2

∂g

∂x3

∂k

∂x1− ∂f

∂x2

∂h

∂x1

∂g

∂x1

∂k

∂x3+

∂f

∂x2

∂h

∂x1

∂g

∂x3

∂k

∂x1

♦♥t x1, x3x2, x3 st∂f

∂x1

∂h

∂x3

∂g

∂x2

∂k

∂x3− ∂f

∂x1

∂h

∂x3

∂g

∂x3

∂k

∂x2− ∂f

∂x3

∂h

∂x1

∂g

∂x2

∂k

∂x3+∂f

∂x3

∂h

∂x1

∂g

∂x3

∂k

∂x2+

∂g

∂x1

∂k

∂x3

∂f

∂x2

∂h

∂x3− ∂g

∂x1

∂k

∂x3

∂f

∂x3

∂h

∂x2− ∂g

∂x3

∂k

∂x1

∂f

∂x2

∂h

∂x3+

∂g

∂x3

∂k

∂x1

∂f

∂x3

∂h

∂x2

t♦♥ ♣r♠tt♦♥ (fgk) sr ♦♥t x1, x3x2, x3 ♥s

♥♦s ♦♥♥

∂f

∂x1

∂h

∂x3

∂g

∂x2

∂k

∂x3− ∂f

∂x1

∂h

∂x3

∂g

∂x3

∂k

∂x2− ∂f

∂x3

∂h

∂x1

∂g

∂x2

∂k

∂x3+∂f

∂x3

∂h

∂x1

∂g

∂x3

∂k

∂x2+

∂g

∂x1

∂k

∂x3

∂f

∂x2

∂h

∂x3− ∂g

∂x1

∂k

∂x3

∂f

∂x3

∂h

∂x2− ∂g

∂x3

∂k

∂x1

∂f

∂x2

∂h

∂x3+∂g

∂x3

∂k

∂x1

∂f

∂x3

∂h

∂x2+

∂g

∂x1

∂h

∂x3

∂k

∂x2

∂f

∂x3− ∂g

∂x1

∂h

∂x3

∂k

∂x3

∂f

∂x2− ∂g

∂x3

∂h

∂x1

∂k

∂x2

∂f

∂x3+

∂g

∂x3

∂h

∂x1

∂k

∂x3

∂f

∂x2+

∂k

∂x1

∂f

∂x3

∂g

∂x2

∂h

∂x3− ∂k

∂x1

∂f

∂x3

∂g

∂x3

∂h

∂x2− ∂k

∂x3

∂f

∂x1

∂g

∂x2

∂h

∂x3+∂k

∂x3

∂f

∂x1

∂g

∂x3

∂h

∂x2+

∂k

∂x1

∂h

∂x3

∂f

∂x2

∂g

∂x3− ∂k

∂x1

∂h

∂x3

∂f

∂x3

∂g

∂x2− ∂k

∂x3

∂h

∂x1

∂f

∂x2

∂g

∂x3+∂k

∂x3

∂h

∂x1

∂f

∂x3

∂g

∂x2+

∂f

∂x1

∂g

∂x3

∂k

∂x2

∂h

∂x3− ∂f

∂x1

∂g

∂x3

∂k

∂x3

∂h

∂x2− ∂f

∂x3

∂g

∂x1

∂k

∂x2

∂h

∂x3+

∂f

∂x3

∂g

∂x1

∂k

∂x3

∂h

∂x2

♥ ér q r♥r st ♥

♠ê♠ ♦♥ ♠♦♥tr q s ♦♥ts ♥s

x1, x2x1, x3, (x2, x30)2, (x1, x30)2, (x1, x20)2

s♦♥t t♦s ♥s ♦ù réstt

Page 118: Structures de Poisson logarithmiques: invariants

♥♥① P♦♥ts ét qqs é♠♦♥strt♦♥s

é♠♦♥strt♦♥ Pr♦♣♦st♦♥

♦t ♦r r♣♣♦♥s q s G : Ep → F st ♥ ♣♣t♦♥ ♥ér ♥

ts②♠étrq t q ♣♦r t♦t y ∈ E ♣♣t♦♥ ♣rt Gy : En−1 → F st

♥ ♦rs G = 0.

♦t x ∈ L, ♥♦s é♥ss♦♥s s ♣♣t♦♥s ♥érs dx : Ltq(L,P ) → Ltq(L,P )♣r

(dxf)(x1, ..., xq) = ρ(x)f(x1, ..., xq)−q∑

i=1

f(x1, ..., [xi, x], ..., xq)

t Fx : Ltq+1(L,P ) → Ltq(L,P ) é♥ ♣r

(Fx(f))(x1, ..., xq) = f(x, x1, ..., xq).

s ♣♣t♦♥s s♦♥t és ♣r s rt♦♥s

Fy(dxf) = dx(Fy(f))− F[x,y](f)

t

Fx(dρf) = dxf − dρ(Fx(f)).

rt♦♥ ♥t ♥ ♣♣t♦♥ A♥ér d : L → End(Ltq(L,P )) é♥♣r x 7→ dx.

♦♥tr♦♥s q ♣♦r t♦t q ∈ N, d st ♥ r♣rés♥tt♦♥ L Lti(L,P ) ♦s♦♥s tr ♥ ♣r ♣r ♥t♦♥ sr q.

ρ(y)ρ(x)f − ρ(x)ρ(y)f − ρ([x, y])f = 0 ♣♦r t♦t f ∈ P t x, y ∈ L. ♠♦♥tr

q d : L → End(Lt0(L,P )) st ♥ ♠♦r♣s♠ èrs ♣♣♦s♦♥s

②♣♦tès r ♣♦r t♦t 1 ≦ k ≦ q− 1 t s♦t f ∈ Ltq(L,P )). P♦r t♦t z ∈ L,

♦♥

Fz(dydxf) = dy[Fz(dxf)]− F[z,y](dxf)

= dy(dxFz(f)− F[z,x](f)

)− F[z,y](dxf)

= dydxFz(f)− dy(F[z,x](f))

= dydxFz(f)− F[z,x](dyf)− F[[z,x],y](f)− F[z,y](dxf).

♦♥

Fz(dydxf)− Fz(dxdyf) = dydxFz(f)− dxdyFz(f) + (F[[z,x],y] + F[[z,y],x])(f)

= d[x,y]Fz(f)− F[[y,x],z](f)

= (d[x,y]Fz − F[[y,x],z])(f))

= Fz(d[x,y]).

Psq z ∈ L st rtrr ♦♥ ♦♥t ♣rès ♣r♥♣ ♥t♦♥ q d st

♥ ♥ r♣rés♥tt♦♥ L ♣r Ltq(L,P )) ♣♦r t♦t q.♦♥tr♦♥s q r♠♠ s♥t st ♦♠♠tt ♣♦r t♦t q ∈ N t x ∈ L

Ltq(L,P )) dρ //

dx

Ltq+1(L,P ))

dx

Ltq(L,P ))dρ

// Ltq+1(L,P ))

Page 119: Structures de Poisson logarithmiques: invariants

f ∈ Lt0(L,P )) = P, ♦rs ♣♦r t♦t y ∈ L ♦♥

(dxdρf)(y) = ρ(x)(dρf)(y)− (dρf)([y, x])

= (ρ(x)ρ(y)− ρ[y, x])(f)

= ρ(y)ρ(x)(f) = ρ(y)(dxf) = (dρdxf)(x)

♣♣♦s♦♥s q r♠♠ st ♦♠♠tt ♣♦r t♦t 1 ≦ k ≦ q − 1 t s♦t

f ∈ Ltq+1(L,P )); q > 0. ♥ ♣♣q♥t s rt♦♥s t t q d st

♥ ♠♦r♣s♠ èrs ♦♥ ♦t♥t

Fy(dρdxf)− Fy(dxdρf)

= dydxf − dρ[Fy(dxf)]− dx[Fy(dρf)] + F[y,x](dρf)

= dydxf − dρdxFy(f)− dρ(F[y,x])− dx[Fy(dρf)] + d[y,x]f − dρ(F[y,z](f))

= dydxf − dρdx(Fy(f))− dxdyf + dxdρ(Fy(f)) + d[y,x]f

= dxdρ(Fy(f))− dρdx(Fy(f)) = 0.

s ♣r♦♣rétés ♥♦s é♠♦♥tr♦♥s ♣r♦♣♦st♦♥ ♣r ♥t♦♥ sr ♦rr

s ♥s ♣rès é ♣r Pr♦♣♦st♦♥ réstt st r

♣♦r q = 0, 1. ♣♣♦s♦♥s réstt r ♣♦r f ∈ Ltk(L,P )) 1 ≦ k ≦ q − 1

t s♦t f ∈ Ltq(L,P )), q > 0. ♣rès q ♣réè ♦♥

Fx(dρdρf) = dxdρf − dρ[Fx((dρf))] = dxdρf − dρdxf + dρdρ(Fx(f)) = 0

é♠♦♥strt♦♥ Pr♦♣♦st♦♥

♦t a, b ∈ A t u, v ∈ S. s ♣r♦♣rétés Pr♦♣♦st♦♥ ♥♦s és♦♥s q

LH[a

d(u)

u]

(d(v)

v)

= aLH[d(u)

u]

(d(v)

v) + σ[H(

d(u)

u)]

(d(v)

v

)d(a)

= aLH[d(u)

u]

(d(v)

v) +

1

uσ(H d(u))(d(v)

v)d(a)

= aLH[d(u)

u]

(d(v)

v) +

1

uσ(u,−)(d(v)

v)d(a)

= ad( 1uvu, v) +

1

uvu, vd(a).

♣rès Pr♦♣♦st♦♥ ♦♥

LH[d(u)

u]

(bd(v)

v)

= [H(d(u)

u)](b)

d(u)

u+ bL

H[d(u)

u]

(d(v)

v)

=1

uu, bd(v)

v+ bd(

1

uvu, v)

Page 120: Structures de Poisson logarithmiques: invariants

♥♥① P♦♥ts ét qqs é♠♦♥strt♦♥s

♣rt♥t

LH(a

d(u)

u)

(bd(v)

v)

= aLH[d(u)

u]

(bd(v)

v) + σ(H(

d(u)

u)))

(bd(v)

v

)d(a)

=a

uu, bd(v)

v+

b

uvu, vd(a) + abd(

1

uvu, v)

♥ ♥trrtss♥t s rôs u t v ♥♦s ♦t♥♦♥s

LH(b

d(v)

v)

(ad(u)

u) =

b

vv, ad(u)

u+

a

uvv, ud(b) + abd(

1

uvv, u)

Psq ω0(x, y) := [Φ(x)]y ♣♦r t♦t x, y ∈ ΩA(log I)ω(a

d(u)

u, bd(v)

v) =

ab

uvu, v

♦rs

dω(ad(u)

u, bd(v)

v) = d[

ab

uvu, v] = abd[

1

uvu, v] + d(ab).(

1

uvu, v)

= abd[1

uvu, v] + bd(a).(

1

uvu, v) + ad(b).(

1

uvu, v)

é♠♦♥strt♦♥ Pr♦♣♦st♦♥

♦♥t a ∈ A t u, v, w ∈ S. ♣rès ♦r♦r ♦♥ [du

u,dv

v]ω =

d(1

uvu, v) t [da, du

u]ω = d(

1

ua, u).

t♥t ♦♥♥é q strtr P♦ss♦♥ −,− st ♦rt♠q ♣r♥♣ ♦♥

I, ♦♥ 1

uvu, v ∈ A. ♥ ♦♥

[[du

u,dv

v

]

ω

,dw

w

]

ω

=

[d(

1

uvu, v), dw

w

]

ω

= d(1

w 1

uvu, v, w).

[[dv

v,dw

w

]

ω

,du

u

]

ω

=

[d(

1

vwv, w), du

u

]

ω[[dw

w,du

u

]

ω

,dv

v

]

ω

=

[d(

1

uww, u), dv

v

]

ω

.

r ♥ ♣♣q♥t ♠♠ ♦♥ ♦t♥t

1

w 1

uvu, v, w =

1

w(1

uvu, v, w − 1

u2v2u, vuv,w)

=1

uvwu, v, w − 1

wu2vu, vu,w − 1

wuv2u, vv, w

Page 121: Structures de Poisson logarithmiques: invariants

1

u 1

vwv, w, u =

1

u(1

vwv, w, u − 1

v2w2v, wvw, u)

=1

vwuv, w, u − 1

uv2wv, wv, u − 1

uvw2v, ww, u

1

v 1

wuw, u, v =

1

v(1

vuw, u, v − 1

w2u2w, uwu, v)

=1

wuvw, u, v − 1

vvw2uw, uw, v − 1

vwu2w, uu, v.

♥ ♦t♥t ♦♥[[du

u,dv

v

]

ω

,dw

w

]

ω

+

[[dv

v,dw

w

]

ω

,du

u

]

ω

+

[[dw

w,du

u

]

ω

,dv

v

]

ω

=1

uvwu, v, w − 1

wu2vu, vu,w − 1

wuv2u, vv, w

+1

vwuv, w, u − 1

uv2wv, wv, u − 1

uvw2v, ww, u

+1

wuvw, u, v − 1

vvw2uw, uw, v − 1

vwu2w, uu, v

=1

uvw(v, w, u+ w, u, v+ u, v, w)

= 0

r♥èr été é♦ ♥tté ♦ −,−.

é♠♦♥strt♦♥ Pr♦♣♦st♦♥

P♦r q st ♣r♠èr ssrt♦♥ ét♥t ♦♥♥és u, v ∈ S t w ∈ A ♥♦s

♦♥s ♥tté s♥t [[du

u,dv

v

], dw

]=

[d(

1

uvu, v), dw

]= d

( 1

uvu, v, w

).

r

1

uvu, v, w

=

1

uvu, v, w − 1

uv2u, vv, w − 1

vu2u, vu,w

♣r ♦♥séq♥t[[du

u,dv

v

], dw

]= d

(1

uvu, v, w − 1

uv2u, vv, w − 1

vu2u, vu,w

).

tts ♠t♥s ♦♥ [[dv

v, dw

],du

u

]=

[d

(1

vv, w

),du

u

]= d

(1

u

1

vv, w, u

).

Psq1

u

1

vv, w, u

=

1

u

(1

vv, w, u − 1

v2v, wv, u

)=

1

uvv, w, u−

1

uv2v, wv, u

♦♥

[[dv

v, dw

],du

u

]= d

(1

uvv, w, u − 1

uv2v, wv, u

)

t ♦♥[[dw,

du

u

],dv

v

]=

[(1

uw, u

),dv

v

]= d

(1

v

1

uw, u, v

).

Pr rs1

v

1

uw, u, v

=

1

vuw, u, v − 1

vu2w, uu, v.

♦♥

Page 122: Structures de Poisson logarithmiques: invariants

♥♥① P♦♥ts ét qqs é♠♦♥strt♦♥s

[[dw,

du

u

],dv

v

]= d

(1

vuw, u, v − 1

vu2w, uu, v

).

♥tté ♦ −,− ♦♥t ① s sss ♦♥♥ [[du

u,dv

v

], dw

]+

[[dv

v, dw

],du

u

]+

[[dw,

du

u

],dv

v

]= 0.

é♠♦♥strt♦♥ Pr♦♣♦st♦♥

♦♥t a1, a2, a3, u1, u2 t u3 é♥s ♣r s ②♣♦tèss Pr♦♣♦st♦♥

P ♣rès ♠♠ ♥♦s ♦♥s 1

u3 1

u1u2u1, u2, u3+

1

u1 1

u2u3u2, u3, u1+

1

u2 1

u3u1u3, u1, u2

=1

u1u2u3u1, u2, u3 −

1

u3u1u22u1, u2u2, u3 −

1

u3u21u2u1, u2u1, u3+

+1

u1u2u3u2, u3, u1 −

1

u3u1u22u2, u3u2, u1 −

1

u23u1u2u2, u3u3, u1+

1

u1u2u3u3, u1, u2 −

1

u3u21u2u3, u1u1, u2 −

1

u23u1u2u3, u1u3, u2

=1

u1u2u3(u1, u2, u3+ u2, u3, u1+ u3, u1, u2)+

−u2, u3u3u1u22

(u1, u2+ u2, u1)−u1, u2u3u21u2

(u1, u3+ u3, u1)+

−u3, u1u23u1u2

(u2, u3+ u3, u2)♣♥♥t r♦t −,− ét♥t ♥ts②♠étrq ui, uj + uj , ui = 0

♣♦r t♦t (i, j).

♥ tr♠♥ ♣r P ♥ ts♥t ♥tté ♦ −,−.

P ♥ ♣♣q♥t ♠♠ ♦♥ ♦t♥t a1u1

a2u2

u2, a3, u1du3u3

=

(a1u1u2

a2u2, a3, u1 −a1a2u1u22

u2, a3u2, u1)du3u3

=

(a1a2u1u2

u2, a3, u1+a1u1u2

u2, a3a2, u1 −a1a2u1u22

u2, a3u2, u1)du3u3

.

Pr ♥ rs♦♥♥♠♥t ♥♦ ♦♥ é♠♦♥tr s trs ♣r♦♣rétés

é♠♦♥strt♦♥ Pr♦♣♦st♦♥

♣rès Pr♦♣♦st♦♥ ♦♥

[[a1du1u1

, a2du2u2

], a3

du3u3

]+

[[a2du2u2

, a3du3u3

], a1

du1u1

]+

[[a3du3u3

, a1du1u1

], a2

du2u2

]=

Page 123: Structures de Poisson logarithmiques: invariants

a1u1u2

u1, a2u2, a3du3u3

+a3a1u3u1

u1, a2, u3du2u2

+a3u3u1

u1, a2a1, u3du2u2

+

−a3a1u21u3

u1, a2u1, u3du2u2

+a1a3u1

u1, a2d(1

u2u3u2, u3) +

a2u2u1

a1, u2u1, a3du3u3

+

+a3a2u3u2

a1, u2, u3du1u1

+a3u3u2

a1, u2a2, u3du1u1

− a3a2u3u22

a1, u2u2, u3du1u1

+

a2a3u2

a1, u2d(1

u1u3u1, u3) +

a1a2u1u2

u1, u2, a3du3u3

− a1a2u1u22

u1, u2u2, a3du3u3

+

−a1a2u21u2

u1, u2u1, a3du3u3

+a3a1u3

a2, u3d(1

u1u2u1, u2) +

a3a2u3

a1, u3d(1

u1u2u1, u2)

+a1a2a3d(1

u3 1

u1u2u1, u2, u3)

a2u2u3

u2, a3u3, a1du1u1

+a1a2u1u2

u2, a3, u1du3u3

+a1u1u2

u2, a3a2, u1du3u3

+

−a1a2u22u1

u2, a3u2, u1du3u3

+a2a1u2

u2, a3d(1

u3u1u3, u1) +

a3u3u2

a2, u3u2, a1du1u1

+

+a1a3u1u3

a2, u3, u1du2u2

+a1u1u3

a2, u3a3, u1du2u2

− a1a3u1u23

a2, u3u3, u1du2u2

+

a3a1u3

a2, u3d(1

u2u1u2, u1) +

a2a3u2u3

u2, u3, a1du1u1

− a2a3u2u23

u2, u3u3, a1du1u1

+

−a2a3u22u3

u2, u3u2, a1du1u1

+a1a2u1

a3, u1d(1

u2u3u2, u3) +

a1a3u1

a2, u1d(1

u2u3u2, u3)

+a2a3a1d(1

u1 1

u2u3u2, u3, u1)

a3u3u1

u3, a1u1, a2du2u2

+a2a3u2u3

u3, a1, u2du1u1

+a2u2u3

u3, a1a3, u2du1u1

+

−a2a3u23u2

u3, a1u3, u2du1u1

+a3a2u3

u3, a1d(1

u1u2u1, u2) +

a1u1u3

a3, u1u3, a2du2u2

+

+a2a1u2u1

a3, u1, u2du3u3

+a2u2u1

a3, u1a1, u2du3u3

− a2a1u2u21

a3, u1u1, u2du3u3

+

a1a2u1

a3, u1d(1

u3u2u3, u2) +

a3a1u3u1

u3, u1, a2du2u2

− a3a1u3u21

u3, u1u1, a2du2u2

+

−a3a1u23u1

u3, u1u3, a2du2u2

+a2a3u2

a1, u2d(1

u3u1u3, u1) +

a2a1u2

a3, u2d(1

u3u1u3, u1)

+a3a1a2d(1

u2 1

u3u1u3, u1, u2).

♥ rt s s ♥térrs été sss st éq♥t à

[[a1du1u1

, a2du2u2

], a3

du3u3

]+

[[a2du2u2

, a3du3u3

], a1

du1u1

]+

[[a3du3u3

, a1du1u1

], a2

du2u2

]=

a1u1u2

u2, a3 (u1, a2+ u2, a1)du3u3

Page 124: Structures de Poisson logarithmiques: invariants

♥♥① P♦♥ts ét qqs é♠♦♥strt♦♥s

a3a1u3u1

(u1, a2, u3+ a2, u3, u1+ u3, u1, a2)du2u2

+u1, a2a3u3u1

(a1, u3+ u3, a1)du2u2

+−u1, a2a3a1u21u3

(u1, u3+ u3, u1)du2u2

+

a1a3u1

(u1, a2+ a2, u1) d(1

u2u3u2, u3) + a1, u2

a2u2u1

(u1, a3+ a3, u1)du3u3

+a3a2u3u2

(a1, u2, u3+ u2, u3, a1+ u3, a1, u2)du1u1

+a2, u3a3u3u2

(a1, u2+ u2, a1+)du1u1

− u2, u3a3a2u3u22

(a1, u2+ u2, a1)du1u1

+

a2a3u2

a1, u2d(

1

u1u3u1, u3+

1

u3u1u3, u1

)

+a1a2u1u2

(u1, u2, a3+ u2, a3, u1+ a3, u1, u2)du3u3

+

−u2, a3a1a2u1u22

(u1, u2+ u2, u1)du3u3

− u1, u2a1a2u21u2

(u1, a3+ a3, u1)du3u3

+a3a1u3

a2, u3d(1

u1u2(u1, u2+ u2, u1))) +

a3a2u3

d(1

u1u2u1, u2 (a1, u3+ u3, a1))+

u3, a1a2u2u3

(u2, a3+ a3, u2)du1u1

+a2a1u2

(u2, a3+ a3, u2) d(1

u3u1u3, u1)+

a3, u1a1u1u3

(a2, u3+ u3, a2)du2u2

− u3, u1a1a3u1u23

(a2, u3+ u3, a2)du2u2

−u3, a1a2a3u2u23

(u2, u3+ u3, u2)du1u1

+a1a2u1

a3, u1d(1

u2u3(u2, u3) + u3, u2))

+a1a2a3d

(1

u3 1

u1u2u1, u2, u3+

1

u1 1

u2u3u2, u3, u1+

1

u2 1

u3u1u3, u1, u2

)= 0.

é♠♦♥strt♦♥ Pr♦♣♦st♦♥

é♦ s ♣r♦♣rétés s strtrs P♦ss♦♥ ♦rt♠qs ♣r♥♣s

étés à Pr♦♣♦st♦♥ q ♦♥ s étés q s♥t

[[a1

du1u1

, a2du2u2

]ω, b3dv3

]

ω

=a1u1u2

u1, a2u2, b3dv3 +b3a1u1

u1, a2, v3du2u2

+

b3u1

u1, a2a1, v3du2u2

− b3a1u21

u1, a2u1, v3du2u2

+a1b3u1

u1, a2d(1

u2u2, v3)+

a2u2u1

a1, u2u1, b3dv3 +b3a2u2

a1, u2, v3du1u1

+b3u2

a1, u2a2, , v3du1u1

+

−b3a2u22

a1, u2u2, v3du1u1

+a2b3u2

a1, u2d(1

u1u1, v3) +

a2a1u1u2

u1, u2, b3dv3+

−a1a2u21u2

u1, u2u1, b3dv3 −a1a2u1u22

u1, u2u2, b3dv3 + b3a1a2, v3d(1

u1u2u1, u2)

+b3a2a1, v3d(1

u1u2u1, u2) + a1a2b3d(

1

u1u2u1, u2, v3).

Page 125: Structures de Poisson logarithmiques: invariants

[[a2

du2u2

, b3dv3]ω, a1du1u1

]

ω

=a2u2

u2, b3v3, a1du1u1

+a1a2u1u2

u2, b3, u1dv3

+a1u1u2

u2, b3a2, u1dv3 −a1a2u1u22

u2, b3u2, u1dv3 +a1a2u2

u2, b3d(1

u1v3, u1)

+b3u2

a2, v3u2, a1du1u1

+a1b3u1

a2, v3, u1du2u2

+a1u1

a2, v3b3, u2du2u2

+a1b3a2, v3d(1

u1u2u2, u1) +

a2b3u2

u2, v3, a1du1u1

− a2b3u22

u2, a1u2, v3du1u1

+a1a2u1

b3, u1d(1

u2u2, v3) +

a1b3u1

a2, u1d(1

u2u2, v3)+

a2b3a1d(1

u1 1

u2u2, v3, u1)

t[[b3dv3, a1

du1u1

]ω, a2du2u2

]

ω

=b3u1

v3, a1u1, a2du2u2

+a2b3u2

v3, a1, u2du1u1

+a2u2

v3, a1b3, u2du1u1

+ b3a2v3, a1d(1

u1u2u1, u2) +

a1u1

b3, u1v3, a2du2u2

+a2a1u1u2

b3, u1, u2dv3 +a2u1u2

b3, u1a1, u2dv3 −a2a1u21u2

b3, u1u1, u2dv3+a1a2u1

b3, u1d(1

u2v3, u2) +

b3a1u1

v3, u1, a2du2u2

− b3a1u21

v3, u3u1, a2du2u2

+a1a2u2

b3, u2d(1

u1v3, u1) +

a2b3u2

a1, u2d(1

u1v3, u1)+

a1b3a2d(1

u2 1

u1v3, u1, u2).

r ♠♠r r♦t r♥èr été ♣t sérr s♦s ♦r♠

u2, b3a1u1u2

(u1, a2+ a2, u1) dv3 +b3u1

u1, a2 (a1, v3+ v3, a1)du2u2

+

b3a1u1

(u1, a2, v3+ v3, u1, a2+ a2, v3, u1+)du2u2

+

−u1, a2b3a1u21

(u1, v3+ v3, u1)du2u2

+a1b3u1

(u1, a2+ a2, u1) d(1

u2u2, v3)+

a2u2u1

a1, u2(u1, b3+ b3, u1)dv3 + a2, v3b3u2

(a1, u2+ u2, a1)du1u1

+

b3a2u2

(a1, u2, v3+ u2, v3, a1+ v3, a1, u2)du1u1

+

−u2, v3b3a2u22

(a1, u2+ u2, a1)du1u1

+a2b3u2

a1, u2d(1

u1(u1, v3+ v3, u1))+

a2a1u1u2

(u1, u2, b3+ u2, b3, u1+ b3, u1, u2)dv3+

−u1, u2a1a2u21u2

(u1, b3+ b3, u1)dv3 − u2, b3a1a2u1u22

(u1, u2+ u2, u1dv3)dv3

+b3a1a2, v3d(1

u1u2(u2, u1+ u1, u2)) + b3a2(a1, v3+ v3, a1)d(

1

u1u2u1, u2)

+a1a2b3d(1

u1u2u1, u2, v3+

1

u1 1

u2u2, v3, u1+

1

u2 1

u1v3, u1, u2)+

v3, a1a2u2

(u2, b3+ b3, u2)du1u1

+a1a2u2

(u2, b3+ b3, u2)d(1

u1v3, u1)

+b3, u2a1u1

(a2, v3+ v3, a2)du2u2

++b3, u1a1a2u1

d(1

u2(u2, v3+ v3, u2)).

Page 126: Structures de Poisson logarithmiques: invariants

♥♥① P♦♥ts ét qqs é♠♦♥strt♦♥s

è é♠♦♥strt♦♥

é♠♦♥strt♦♥ Pr♦♣♦st♦♥

♦♥t u1, u3 ∈ S a1, a3, b2 t v2 ♥s A ♣rès r♠rq ♦s ♦♥s [[a1

du1u1

, b2dv2]ω, a3du3u3

]

ω

+

[[b2dv2, a3

du3u3

]ω, a1du1u1

]

ω

+

[[a3

du3u3

, a1du1u1

]ω, b2dv2

]

ω

=

a1u1

u1, b2v2, a3du3u3

+a3a1u3u1

u1, b2, u3dv3 +a3u3u1

a1, u3u1, b2dv3+

−a3a1u3u21

u1, b2u1, u3dv2 +a1a3u1

u1, b2d(1

u3v2, u3) +

b2u1

a1, v2u1, a3du3u3

+

a3b2u3

a1, v2, u3du1u1

+a3u3

b2, u3a1, v2du1u1

+ a3b2a1, v2d(1

u1u3u1, u3)

+a1b2u1

u1, v2, a3du3u3

− a1b2u21

u1, a3u1, v2du3u3

+a3a1u3

b2, u3d(1

u1u1, v2)

+a3b2u3

a1, u3d(1

u1u1, v2) + a1b2a3d(

1

u3 1

u1u1, v2, u3)

+b2u3

v2, a3u3, a1du1u1

+a1b2u1

v2, a3, u1du3u3

+a1u1

v2, a3b2, u1du3u3

+ b2a1v2, a3d(1

u3u1u3, u1) +

a3u3

b2, u3v2, a1du1u1

+a1a3u3u1

b2, u3, u1dv2 +a1u3u1

b2, u3a3, u1dv2 −a1a3u23u1

b2, u3u3, u1dv2+a3a1u3

b3, u3d(1

u1v2, u1) +

b2a3u3

v2, u3, a1du1u1

− b2a3u23

v2, u3u3, a1du1u1

+a3a1u1

b2, u1d(1

u3v2, u3) +

a1b2u1

a3, u1d(1

u3v2, u3)+

a3b3a1d(1

u1 1

u3v2, u3, u1)

+a3u3u1

u3, a1u1, b2dv2 +b2a3u3

u3, a1, v2du1u1

+

b2u3

u3, a1a3, v2du1u1

− b2a3u23

u3, a1u3, v2du1u1

+a3b2u3

u3, a1d(1

u1u1, v2)+

a1u1u3

a3, u1u3, b2dv2 +b2a1u1

a3, u1, v2du3u3

+b2u1

a3, u1a1, v2du3u3

+

−b2a1u21

a3, u1u1, v2du3u3

+a1b2u1

a3, u1d(1

u3u3, v2) +

a1a3u3u1

u3, u1, b2dv2+

−a3a1u23u1

u3, u1u3, b2dv2 −a3a1u3u21

u3, u1u1, b2dv2 + b2a3a1, v2d(1

u3u1u3, u1)

+b2a1a3, v2d(1

u3u1u3, u1) + a3a1b2d(

1

u3u1u3, u1, v2).

♥ ♥s

Page 127: Structures de Poisson logarithmiques: invariants

[[a1

du1u1

, b2dv2]ω, a3du3u3

]

ω

+

[[b2dv2, a3

du3u3

]ω, a1du1u1

]

ω

+

[[a3

du3u3

, a1du1u1

]ω, b2dv2

]

ω

= v2, a3a1u1

(u1, b2+ b2, u1)du3u3

+ u1, b2a3u3u1

(a1, u3+ u3, a1)dv2a3a1u3u1

(u1, b2, u3+ b2, u3, u1+ u3, u1, b2)dv2+

−u1, b2a3a1u3u21

(u1, u3+ u3, u1)dv2 +a1a3u1

(u1, b2+ b2, u1)d(1

u3v2, u3)+

a3b2u3

(a1, v2, u3+ u3, a1, v2+ v2, u3, a1)du1u1

+

+b2, u3a3u3

(a1, v2+ v2, a1)du1u1

+ a3b2a1, v2d(1

u1u3(u1, u3+ u3, u1)

+(a1b2u1

u1, v2, a3+ v2, a3, u1+ a3, u1, v2)du3u3

−u1, v2a1b2u21

(u1, a3+ a3, u1)du3u3

+a3a1u3

b2, u3d(1

u1(u1, v2+ v2, u1))+

a3b2u3

(a1, u3+ u3, a1)d(1

u1u1, v2) +

b2u3

v2, a3(u3, a1+ a1, u3)du1u1

+b2a1(v2, a3+ a3, v2)d(1

u3u1u3, u1) + a3, u1

a1u3u1

(b2, u3+ u3, b2dv2

−a1a3u23u1

b2, u3(u3, u1+ u1, u3)dv2 −b2a3u23

u3, a1(v2, u3+ v2, u3)du1u1

.

é♠♦♥strt♦♥ é♦rè♠

♦t αi =dh

h+ α1

i , ♦♥ (LH(α1)

α2|H(α3))

=

(1

hLH(dh)α

12|1

hH(dh)

)−

(H(dh)(α1

2)

h

dh

h| 1hH(dh)

)+

(1

hLH(dh)α

12|H(α1

3)

)−

(H(dh)(α1

2)

h

dh

h|H(α1

3)

)−

(H(α1

1)h

h

dh

h| 1hH(dh)

)−

(H((α1

1)

h

dh

h|H(α1

3)

)+

(1

hLH(α1

1)dh|

1

hH(dh)

)+

(1

hLH(α1

1)dh|H(α1

3)

)+

(LH(α1

1)α

12|1

hH(dh)

)+(LH(α1

1)α

12|H(α1

3))

ér♦♥s r♥èr été s♦s ♦r♠ s♥t

(LH(α1)

α2|H(α3))

=1

h2(LH(dh)α

12|H(dh)

)+

1

h

(LH(dh)α

12|H(α1

3))

−H(dh)(α1

2)

h2(dh|H(α1

3))

− H(α11)h

h2(dh|H(α1

3))

+1

h2

(LH(α1

1)dh|H(dh)

)+

1

h

(LH(α1

1)dh|H(α1

3))+

1

h

(LH(α1

1)α

12|H(dh)

)+(LH(α1

1)α

12|H(α1

3)).

♥ s♦♠♠♥t s♦s ♣r♠tt♦♥ ②q ♦♥ ♦t♥t (LH(α1)

α2|H(α3))+ =

1

h2(LH(dh)α

12|H(dh)

)+

1

h

(LH(dh)α

12|H(α1

3))

−H(dh)α1

2

h2(dh|H(α1

3))

− H(α11)(h)

h2(dh|H(α1

3))

+1

h2

(LH(α1

1)dh|H(dh)

)+

1

h

(LH(α1

1)dh|H(α1

3))

+1

h

(LH(α1

1)α

12|H(dh)

)+

(LH(α1

1)α

12|H(α1

3))

+

1

h2(LH(dh)α

13|H(dh)

)+

1

h

(LH(dh)α

13|H(α1

1))

− H(dh)(α13)

h2(dh|H(α1

1))

Page 128: Structures de Poisson logarithmiques: invariants

♥♥① P♦♥ts ét qqs é♠♦♥strt♦♥s

H(α12)h

h2(dh|H(α1

1))

+1

h2

(LH(α1

2)dh|H(dh)

)+

1

h

(LH(α1

2)dh|H(α1

1))

+

1

h

(LH(α1

2)α

13|H(dh)

)+(LH(α1

2)α

13|H(α1

1))+

1

h2(LH(dh)α

11|H(dh)

)+1

h

(LH(dh)α

11|H(α1

2))−

H(dh)(α11)

h2(dh|H(α1

2))

− H(α13)h

h2(dh|H(α1

2))

+1

h2

(LH(α1

3)dh|H(dh)

)+

1

h

(LH(α1

3)dh|H(α1

2))+

1

h

(LH(α1

3)α

11|H(dh)

)+(LH(α1

3)α

11|H(α1

2))

♥ ♦t♥t (LH(α1)

α2|H(α3))+ =

[(LH(α1

3)α

11|H(α1

2))+(LH(α1

1)α

12|H(α1

3))+(LH(α1

2)α

13|H(α1

1))]

1

h

[(LH(α1

3)α

11|H(dh)

)+(LH(α1

1)dh|H(α1

3))+(LH(dh)α

13|H(α1

1))]

+

1

h

[(LH(α1

3)dh|H(α1

2))+(LH(dh)α

12|H(α1

3))+(LH(α1

2)α

13|H(dh)

)]+

1

h2

[(LH(α1

3)dh|H(dh)

)+(LH(dh)dh|H(α1

3))+(LH(dh)|α1

3H(dh))]

+

1

h2

[(LH(α1

3)dh|H(dh)

)+(LH(dh)dh|H(α1

3))+(LH(dh)α

13|H(dh)

)]+

1

h

[(LH(dh)α

11|H(α1

2))+(LH(α1

1)α

12|H(dh)

)+(LH(α1

2)dh|H(α1

1))]

+

− 1

h2[H(α1

1)(dh)(dh|H(α1

2))+H(α1

3)(dh)(dh|H(α1

2))]

+

− 1

h2[H(α1

3)(dh)(dh|H(α1

1))+H(α1

2)(dh)(dh|H(α1

1))]

+

− 1

h2[H(dh)(α1

2)(dh|H(α1

3))+H(dh)(α1

1)(dh|H(α1

3))]

Psq H st ♠t♦♥♥ s rt♦♥s s♦♥t ♥s ♥ ♦♥

(LH(α1)

α2|H(α3))+ =

−H(dh)(α11)

h2(dh|H(α1

2))− H(dh)(α1

3)

h2(dh|H(α1

2))

−H(dh)(α13)

h2(dh|H(α1

1))− H(dh)(α1

2)

h2(dh|H(α1

1))

−H(dh)(α12)

h2(dh|H(α1

3))− H(dh)(α1

1)

h2(dh|H(α1

3))

= −[H(α1

1)(dh)

h2(dh|H(α1

2))+H(dh)(α1

2)

h2(dh|H(α1

1))]

−[H(α1

3)(dh)

h2(dh|H(α1

2))+H(dh)(α1

2)

h2(dh|H(α1

3))]

−[H(α1

3)(dh)

h2(dh|H(α1

1))+H(dh)(α1

1)

h2(dh|H(α1

3))]

= 0.

Page 129: Structures de Poisson logarithmiques: invariants

♥ rt t qq s♦t αi = α0i

dh

h+ α1

i ∈ ΩX(logD) qq s♦t i ∈1, 2, 3 ♦♥

Lα01

hH(dh)+H(α1

1)

(α02

dh

h+ α1

2) = α01

H(dh)

h.(α0

2)dh

h

+α01

hLH(dh)α

12 +H(dh).α1

2

dα01

h− α0

1

H(dh)

h.α1

2

dh

h

+H(α11).(α

02)dh

h− α0

2

H(α11)

h.dh

dh

h+α02

hLH(α1

1)dh+ LH(α1

1)α

12

s♥ st q

(LH(α1)

α2|H(α3))=

(α01

hH(dh)(α0

2)dh

h|α

03

hH(dh)

)+

(α01

hH(dh)(α0

2)dh

h|H(α1

3)

)+

(α01

hLH(dh)α

12|α03

hH(dh)

)+

(α01

hLH(dh)α

12|H(α1

3)

)+

(H(dh).α1

2

dα01

h|α

03H(dh)

h

)+

(H(dh).α1

2

dα01

h|H(α1

3)

)+

(α01

H(dh).α12

h

dh

h|α0

3

H(dh)

h

)+

(α01

H(dh).α12

h

dh

h|H(α1

3)

)+

(H(α1

1)(α02)dh

h|α

03

hH(dh)

)+

(H(α1

1)(α02)dh

h|H(α1

3)

)−

(α02

H(α11).dh

h

dh

h|α

03

hH(dh)

)−

(α02

H(α11)

h.dh

dh

h|H(α1

3)

)+

(α02

hLH(α1

1)dh|

α03

hH(dh)

)+

(α02

hLH(α1

1)dh|H(α1

3)

)+

(LH(α1

1)α

12|α03

hH(dh)

)+(LH(α1

1)α

12|H(α1

3)).

rtèr ♥ts②♠étrq r♦t P♦ss♦♥ ♦♥ ét(LH(α1)

α2|H(α3))+ =

α01H(dh)(α0

2)

h2(dh|H(α1

3))+α01α

03

h2(LH(dh)α

12|H(dh)

)+

α01

h

(LH(dh)α

12|H(α1

3))+ α0

3

H(dh).α12

h2(dα0

1|H(dh))+H(dh).α1

2

h

(dα0

1|H(α13))+

α03α

02

h2

(LH(α1

1)dh|H(dh)

)− α0

1

H(dh).α12

h2(dh|H(α1

3))+H(α1

1)(α02)

h

(dh|H(α1

3))

−α02

H(α11).dh

h2(dh|H(α1

3))+α02

h

(LH(α1

1)dh|H(α1

3))+α03

h

(LH(α1

1)α

12|H(dh)

)+

(LH(α1

1)α

12|H(α1

3))+α02H(dh)(α0

3)

h2(dh|H(α1

1))+α02α

01

h2(LH(dh)α

13|H(dh)

)+

α02

h

(LH(dh)α

13|H(α1

1))+ α0

1

H(dh).α13

h2(dα0

2|H(dh))+H(dh).α1

3

h

(dα0

2|H(α11))+

α01α

03

h2

(LH(α1

2)dh|H(dh)

)− α0

2

H(dh).α13

h2(dh|H(α1

1))+H(α1

2)(α03)

h

(dh|H(α1

1))

−α03

H(α12).dh

h2(dh|H(α1

1))+α03

h

(LH(α1

2)dh|H(α1

1))+α01

h

(LH(α1

2)α

13|H(dh)

)+

(LH(α1

2)α

13|H(α1

1))+α02H(dh)(α0

3)

h2(dh|H(α1

1))+α02α

01

h2(LH(dh)α

13|H(dh)

)+

α03

h

(LH(dh)α

11|H(α1

2))+ α0

2

H(dh).α11

h2(dα0

3|H(dh))+H(dh).α1

1

h

(dα0

3|H(α12))+

α02α

01

h2

(LH(α1

3)dh|H(dh)

)− α0

3

H(dh).α11

h2(dh|H(α1

2))+H(α1

3)(α01)

h

(dh|H(α1

2))

−α01

H(α13).dh

h2(dh|H(α1

2))+α01

h

(LH(α1

3)dh|H(α1

2))+α02

h

(LH(α1

3)α

11|H(dh)

)+(

LH(α1

3)α

11|H(α1

2)).

Page 130: Structures de Poisson logarithmiques: invariants

♥♥① P♦♥ts ét qqs é♠♦♥strt♦♥s

♣rès rr♦♣♠♥t ♦♥ ♦t♥t

(LH(α1)

α2|H(α3))+ =

α01

h2[(H(dh)|d(α0

2)) (dh|H(α1

3))+(H(dh)|α1

3

) (dα0

2|H(dh))]

+

α01α

03

h2

[(LH(dh)α

12|H(dh)

)+(LH(α1

2)dh|H(dh)

)+

(LH(dh)dh|H(α1

2))]

+

α01

h

[(LH(dh)α

12|H(α1

3))+(LH(α1

2)α

13|H(dh)

)+(LH(α1

3)dh|H(α1

2))]

+

α03

h2[(H(dh)|α1

2

) (dα0

1|H(dh))+

(H(dh)|dα0

1

) (dh|H(α1

2))]

+

1

h

[(H(dh)|α1

2

) (dα0

1|H(α13))+(dh|H(α1

2)) (dα0

1|H(α13))]

+

α03α

02

h2

[(LH(α1

1)dh|H(dh)

)+(LH(dh)dh|H(α1

1))+

(LH(dh)α

11|H(dh)

)]+

− α01

h2[(H(dh)|α1

2

) (dh|H(α1

3))+(dh|H(α1

2)) (dh|H(α1

3))]

+

1

h

[(H(α1

1)|dα02

) (dh|H(α1

3))+(H(α1

1)|dα02

) (H(dh)|α1

3

)]+

− α02

h2[(H(α1

1)|dh) (dh|H(α1

3))+(H(α1

1)|dh) (H(dh)|α1

3

)]+

α02

h

[(LH(α1

1)dh|H(α1

3))+(LH(dh)α

13|H(α1

1))+(LH(α1

3)α

11|H(dh)

)]+

α03

h

[(LH(α1

1)α

12|H(dh)

)+(LH(α1

2)dh|H(α1

1))+(LH(dh)α

11|H(α1

2))]

(LH(α1

1)α

12|H(α1

3))+(LH(α1

2)α

13|H(α1

1))+(LH(α1

3)α

11|H(α1

2))

t q H stst s rt♦♥ ♥tr♥ ♥té s rt♦♥s

♥ rést q(LH(α1)

α2|H(α3))+ = 0

Pr rs ♣♦r t♦s α = α0dh

h+ α1 t β = β0

dh

h+ β1. ♦♥

Page 131: Structures de Poisson logarithmiques: invariants

(H(α)|β

)=

=

(α0H(dh)

h+H(α1)|β0

dh

h+ β1

)

=

(α0

1

hH(dh)|β0

dh

h

)+

(α0

1

hH(dh)|β1

)+

(H(α1)|β0

dh

h

)+ (H(α1|β1))

=α0

h(H(dh)|β1) +

β0h

(H(α1)|dh) + (H(α1)|β1)(H(β)|α

)=

=

(β0H(dh)

h+H(β1)|α0

dh

h+ α1

)

=

(β0H(dh)

h|α0

dh

h

)+α0

h(H(β1)|dh) +

β0h

(H(dh)|α1)) + (H(β1)|α1)

=α0

h(H(β1)|dh) +

β0h

(H(dh)|α1)) + (H(β1)|α1)(H(α)|β

)+(H(β)|α

)=

=α0

h((H(dh)|β1) + (H(β1)|dh)) +

β0h

((H(dh)|α1) + (H(α1)|dh))++(H(β1)|α1) + (β1|H(α1))

= 0 + 0 + 0 + 0

♦ù s♦tr♦♣ Gr(H).

é♠♦♥strt♦♥ ♦r♦r

st r q r♦t é♥t ♥s OX ② é♥t ♥ strtr èr

rst ♦♥ à érr ♥tté ♦ sr s st♦♥s rst♥ts MD.

t♣

♥ s ♦♥♥ u, v ∈ MD −OX t a ∈ OX ♦rs

u, v, aDD = u, 1vv, asD

=1

uvu, v, ass −

1

uv2u, vsv, as.

s♥st ♦♥ q

u, v, aDD+ =1

uvu, v, ass − 1

uv2u, vsv, as +

1

uvv, a, uss −

1

u2va, usv, us +

1

uva, u, vss −

1

uv2u, vsa, vs −

1

u2vu, vsa, us

t♣

♥ s ♦♥♥ v ∈ MD −OX t a, b ∈ OX . ♦rs

a, b, vDD = a, 1vb, vsD =

1

va, b, vss −

1

v2b, va, vs.

♠ê♠ ♥♦s ♦♥s

b, v, aDD = b, 1vv, asD

=1

vb, v, ass −

1

v2v, asb, vs

tv, a, bDD = v, a, bsD

=1

vv, a, bss

.

Page 132: Structures de Poisson logarithmiques: invariants

♥♥① P♦♥ts ét qqs é♠♦♥strt♦♥s

♥ ♥ ét ♦♥ q

a, b, vDD+ =1

va, b, vss −

1

v2b, va, vs+

+1

vb, v, ass −

1

v2v, asb, vs +

1

vv, a, bss

=1

va, b, vss +

1

vb, v, ass +

1

vv, a, bss

= 0

t♣

Pr♥♦♥s u, v, w ∈ MD −OX .

♦rs u, v, wDD = u, 1

vwv, wsD.

s1

vwv, ws ∈ OX ; r

1

vwv, ws = v, wD ∈ OX . ♥ rést q

u, v, wDD = u, 1

vwv, wsD.

=1

uvwu, v, wss −

1

uvw2v, wsu,ws −

1

uwv2v, wsu, vs.

♥ ♥ ét q

u, v, wDD+ =1

uvwu, v, wss −

1

uvw2v, wsu,ws −

1

uwv2v, wsu, vs

+1

uvwv, w, uss −

1

vwu2w, usv, us −

1

vuw2w, usv, ws

+1

uvww, u, vss −

1

wuv2u, vsw, vs −

1

wvu2u, vsw, us

=1

uvw(u, v, wss + v, w, uss + w, u, vss)

= 0.♥s −,−D stst ♥tté ♦ ♥ ♥ ét ♦♥ q st ♥ strtr

èr

é♠♦♥strt♦♥ Pr♦♣♦st♦♥

♦♥t α, β ∈ ΩX(logD) ♦♥

Hα(Hβ) =α1β1h2

h, h,−+ α1

h2h, β1h,−+ α1β

j

hh, xj ,−+ α1

hh, βjxj ,−+

αiβ1h

xi, h,−+ αi

hxi, βjh,− − αiβj

h2xi, hh,−+ αiβjxi, xj ,−+

αixi, βjxj ,−.Hβ(Hα) =β1α1

h2h, h,−+ β1

h2h, α1h,−+ β1

hh, αixi,−+ β1α

i

hh, xi,−+

βjα1

hxj , h,−+ βj

h2xj , α1h,− −+

βjα1

h2xj , hh,−+ βjαixj , xi, +

βjxj , αixi,−.

t

♦♥Hα(Hβ)− Hβ(Hα) =

=α1

h2h, β1h,−+ αiβ1

hxi, h,−+ α1β

j

hh, xj,−+ α1

h2h, βjh,−+

β1h2

α1, hh,−+ β1hαi, hxi,−+ αi

hxi, βjh,−+ βj

hα1, xjh,−−

αiβæ

h2xi, hh,− − α1β

j

h2h, xjh,−+ αiβjxi, xj,−+ αixi, βjxj ,−+

βjαi, xjxi,−

Page 133: Structures de Poisson logarithmiques: invariants

Pr rs ♥♦s ♦♥sH([α, β]) =

=α1

h2h, β1h,−+ β1

h2α1, hh,−+ α1

hh, βjxi,−+ βj

hα1, xjh,−

+α1β

j

hh, xj,− − α1β

j

h2h, xjh,−+ αi

hxi, βjh,−+ β1

hαi, hxi,−+

αiβ1h

xi, h,− − αiβj

h2xi, hh, ,−+ αixi, βjxj ,−+ βjαi, xjxi,−+

αiβjxi, xj,−♥ ♥

H([α, β]) = [Hα, Hβ]

é♠♦♥strt♦♥ Pr♦♣♦st♦♥

st qst♦♥ ♠♥r C[y]dx

x⊕ΩA ♥ strtr èr r strtr

P♦ss♦♥ s♥t

[dx, dy] := dx

t ΩA ♥ èr

②♥t st ①t ♦rt A♠♦s s♥t

0 // ΩA// ΩA ⊕ C[y]

dx

x// C[y]

dx

x// 0

st ♠ttr sr C[y]dx

x♥ strtr èr ♠♥èr à ♥ r ♥

①t♥s♦♥ s♥é r ♣rès ❬ss② t ❪

[γ1 + β1, γ2 + β2] = [γ1, γ2] + [β1, γ2]− [β2, γ1] + [β1, β2]

♦ù γi + βi ∈ ΩA ⊕ C[y]dx

x♣♦r i = 1, 2.

st ♥ strtr èr ♥s ΩA ⊕ C[y]dx

xà ♦♥t♦♥ q ΩA ♥ é

ΩA ⊕C[y]dx

x. st ♦♥ ♠♦♥trr q s r♦ts é♥s ♣r t s♦♥t

é①

P♦s♦♥s γ1 = γ01dx

x, β1 = β0

1dx+ β11dy t γ2 = γ02

dx

x, β2 = β0

2dx+ β12dy.

Pr ♥ rt ♦♥ ♦t♥t

[γ1, γ2] =

(γ01xx, γ02+

γ02xγ01 , x

)dx

x,

[β1, β2] =(β01x, β0

2+ β02β0

1 , x+ β12β0

1 , y+ β11y, β0

2+ (β01β

12 − β1

1β02))dx +(

β01x, β1

2+ β02β1

1 , x+ β11y, β1

2+ β12β1

1 , y)dy,

[β1, γ2] =γ02xβ0

1 , xdx+γ02xβ1

1 , xdy + (β01x, γ02+ β1

1y, γ02)dx

x,

[β2, γ1] =γ01xβ0

2 , xdx+γ01xβ1

2 , xdy + (β02x, γ01+ β1

2y, γ01)dx

x.

Page 134: Structures de Poisson logarithmiques: invariants

♥♥① P♦♥ts ét qqs é♠♦♥strt♦♥s

s étés q ♣réè♥t ♦♥ ét[γ1 + β1, γ2 + β2] = [γ1, γ2] + [β1, γ2]− [β2, γ1] + [β1, β2] =(γ01xx, γ02+

γ02xγ01 , x+ β0

1x, γ02+ β11y, γ02 − β0

2x, γ01 − β12y, γ01

)dx

x+

(γ02xβ0

1 , x −γ01xβ0

2 , x+ β01x, β0

2+ β02β0

1 , x+ β12β0

1 , y+ β11y, β0

2+ (β01β

12 − β1

1β02)

)dx+

(γ02xβ1

1 , x −γ01xβ1

2 , x+ β01x, β1

2+ β02β1

1 , x+ β11y, β1

2+ β12β1

1 , y)dy.

Pr rs γ1+β1 = (γ01 +xβ01)dx

x+β1

1dy, γ2+β2 = (γ02 +xβ02)dx

x+β1

2dy. ♥ ♣♣q♥t

r♦t é♥ ♣r ♦♥ ♦t♥t

[γ1 + β1, γ2 + β2] =

= [(γ01 + xβ01)dx

x, (γ02 + xβ0

2)dx

x] + [(γ01 + xβ0

1)dx

x, β1

2dy]

+ [β11dy, (γ

02 + xβ0

2)dx

x] + [β1

1dy, β12dy]

=(γ01 + xβ0

1)

xx, γ02 + xβ0

2dx

x+

(γ02 + xβ02)

xγ01 + xβ0

1 , xdx

x

+(γ01 + xβ0

1)

xx, γ12dy + β1

2γ01 + xβ01 , y

dx

x

+ β11y, γ02 + xβ0

2dx

x+γ02 + xβ0

2

xβ1

1 , xdy+ β1

1y, β12dy + β1

2β12 , ydy

= (γ01xx, γ02+ β0

1x, γ02+γ02xγ01 , x+ β0

2γ01 , x+ β12γ01 , y+ β1

1y, γ02)dx

x+ (β0

1x, β02+ γ01x, β0

2+ β02β0

1 , x+ γ02β01 , x+ β1

2β01 , y+ βy, β0

2+β12β

01 − β1

1β02)dx

+ (γ01xx, β1

2+ β01x, β1

2+γ02xβ1

1 , x+ β02β1

1 , x+ β11y, β1

2+ β12β1

1 , y)dy.

♥ ♥ été ré

Page 135: Structures de Poisson logarithmiques: invariants

é♠♦♥strt♦♥ ♠♠

♦♥t α, β t a ♦♠♠ ♥s ②♣♦tès ♠♠ ♥

[α, aβ] =

aα01

xx, β0

1dx

x+α01β

01

xx, adx

x+aβ0

1

xα0

1, xdx

x+α01a

xx;β1

1dy+

+α01β

11

xx, ady + aβ1

1α01, y

dx

x+ α1

1ay, β01dx

x+ α1

1β01y, a

dx

x+

+ aβ01α1

1, xdy + α11ay, β1

1dy + α11β

11y, ady + aβ1

1α11; ydy.

=

a(α01

xx, β0

1dx

x+β01

xα0

1, xdx

x+α01

xx;β1

1dy + β11α0

1, ydx

x

+ α11y, β0

1dx

x+ β0

1α11, xdy + α1

1y, β11dy + β1

1α11; ydy)

+ ((α01

xx, a+ α1

1y, a)β01

dx

x+ (

α01

xx, a+ α1

1y, a)β11dy)

=

a(α01

xx, β0

1dx

x+β01

xα0

1, xdx

x+α01

xx;β1

1dy + β11α0

1, ydx

x

+ α11y, β0

1dx

x+ β0

1α11, xdy + α1

1y, β11dy + β1

1α11; ydy)

+ (α01

xx, a+ α1

1y, a)β= H(α)(a).β + a[α, β].

é♠♦♥strt♦♥ Pr♦♣♦st♦♥

♦♥t α = α01

dx

x+ α1

1dy t β = β01

dx

x+ β1

1dy ♥s ∈ ΩA(log I). ♥

H([α, β]) =1

x(α01

xx, β0

1+β01

xα0

1, x+ α11y, β0

1+ β11α0

1, y)x,−

(α01

xx, β1

1+β01

xα1

1, x+ α11y, β1

1+ β11α1

1, y)y,−

Pr rs ♦♥

H(α)H(β) =α01β

01

x2x, x,−+ α0

1

x2x, β0

1x,−+ α01β

11

xx, y,−+

α01

xx, β1

1y,−+ α11β

01

xy, x,−+ α1

1

xy, β0

1x,−+

−α11β

01

x2y, xx,−+ α1

1β11y, y,−+ α1

1y, β11y,−

H(β)H(α) =β01α

01

x2x, x,−+ β0

1

x2x, α0

1x,−+ β01α

11

xx, y,−+

β01

xx, α1

1y,−+ β11α

01

xy, x,−+ β1

1

xy, α0

1x,−+

−β11α

01

x2y, xx,−+ β1

1α11y, y,−+ β1

1y, α11y,−

H(α)H(β)− H(β)H(α) = H([α, β]) +

α11β

01

x(y, x,− − 1

xy, xx,− − x, y,−)

α11β

01

x(x, y,− − y, x,−+ 1

xy, xx,−).

Page 136: Structures de Poisson logarithmiques: invariants

♥♥① P♦♥ts ét qqs é♠♦♥strt♦♥s

r

y, x,− − 1

xy, xx,− − x, y,− =

= (y, x,−+ x, −, y+ x,−)= (y, x,−+ x, −, y+ −, y, x)= 0

t

x, y,− − y, x,−+ 1

xy, xx,− =

= x, y,−+ y, −, x − x,−= x, y,−+ y, −, x+ −, x, y= 0

♦ù réstt

é♠♦♥strt♦♥ Pr♦♣♦st♦♥

st qst♦♥ ♠♦♥trr q qq s♦t α0, α1 t α2 ♥s ΩA(log I) ♦♥ 0 =

dρω (ω)(α0, α1, α2) = ρω(α0)ω(α1, α2)−ρω(α1)ω(α0, α2)+ρω(α2)ω(α0, α1)−ω([α0, α1], α2)+

ω([α0, α2], α1)−ω([α1, α2], α0.) st r sr s éé♠♥ts é♥értrs ΩA(log I).P♦r α0 =

du0u0

, α1 =du1u1

, α2 =du2u2

♦♥

dρω (ω)(α0, α1, α2) =1

u0u0,

1

u1u2u1, u2 −

1

u1u1,

1

u0u2u0, u2+

1

u2u2,

1

u0u1u0, u1

− 1

u2 1

u0u1u0, u1, u2+

1

u1 1

u0u2u0, u2, u1 −

1

u0 1

u1u2u1, u2, u0

=1

u0u1u2u0, u1, u2 −

1

u0u1u22u1, u2u0, u2

− 1

u0u2u21u1, u2u0, u1 −

1

u1u0u2u1, u0, u2+

1

u2u1u20u0, u2u1, u0

+1

u22u1u0u0, u2u1, u2+

1

u0u1u2u2, u0, u1 −

1

u2u1u20u0, u1u2, u0

− 1

u2u0u21u0, u1u2, u1+

1

u2u0u1u0, u1, u2+

1

u2u20u1u0, u1u0, u2

+1

u1u0u2u0, u2, u1 −

1

u1u20u2u0, u2u0, u1 −

1

u1u0u22u0, u2u2, u1

− 1

u0u1u2u1, u2, u0+

1

u0u21u2u1, u2u1, u0+

1

u0u1u22u1, u2u2, u2.

♥ ♣♣q♥t ① ♦s ♥tté ♦ ♦♥ ♦t♥t dρω (ω)(α0, α1, α2) = 0. ♠ê♠

♣♦r α0 =du0u0

, α2 =du1u1

, α2 = du2

Page 137: Structures de Poisson logarithmiques: invariants

dρω (ω)(α0, α1, α2) =1

u0u0,

1

u1u1, u2 −

1

u1u1,

1

u0u0, u2+ u2,

1

u0u1u0, u1

=1

u0u1u0, u1, u2 −

1

u0u21u1, u2u0, u1 −

1

u1u0u1, u0, u2+

1

u1u20u0, u2u1, u0

+1

u0u1u2, u0, u1 −

1

u0u21u0, u1u2, u1 −

1

u20u1u0, u1u2, u0 −

1

u0u1u0, u1, u2

+1

u0u21u0, u1u1, u2+

1

u20u1u0, u1u0, u2+

1

u1u0u0, u2, u1 −

1

u1u20u0, u2u0, u1

− 1

u0u1u1, u2, u0+

1

u0u21u1, u2u1, u0 = 0.

♠ê♠ ♦♥ ♠♦♥tr dρω (ω)(α0, α1, α2) = 0 ♣♦r α0 =du0u0

, α1 = du1, α2 = du2 ♥s q

♣♦r α0 = du0, α1 = du1, α2 = du2.

é♠♦♥strt♦♥ Pr♦♣♦st♦♥

P♦r ωi = aiduiui

+ bidvi ωj = ajdujuj

+ bjdvj t f ∈ A ♦♥

[ωi, fωj ] = ρω(ωi)(a)ωj + f [ωi, ωj ]

♥ t

Page 138: Structures de Poisson logarithmiques: invariants

♥♥① P♦♥ts ét qqs é♠♦♥strt♦♥s

[ωi, fωj ] = [aiduiui, faj

dujuj

] + [aiduiui, fbjdvj ] + [bidvi, faj

dujuj

]

=aiui

ui, faj+faiuj

ai, ujduiui

+ faiajd(1

uiujui, uj) +

aiui

ui, fbjdvj+

fbjai, vjduiui

+ faid(1

uiui, vj) + bivi, faj

dujuj

+fajuj

bi, ujdvi+

fbiajd(1

ujvi, uj) + bivi, fbjdvj + fbjbi, vjdvi + fbibjd(vi, vj)

=faiui

ui, ajdujuj

+aiajui

ui, fdujuj

+fajuj

ai, ujduiui

+

faiajd(1

uiujui, uj) +

faiui

ui, bjdvj +aibjui

ui, fdvj+

fbjai, vjduiui

+ faibjd(1

uiui, vj) + bifvi, aj

dujuj

+

fbivi, bjdvj + bibjvi, fdvj + fbjbi, vjdvi + fbibjd(vi, vj)= f(

aiui

ui, ajdujuj

+ajuj

ai, ujduiui

+ aiajd(1

uiujui, uj)

aiui

ui, bjdvj + bjai, vjduiui

+ aibjd(1

uiui, vj)

bivi, bjdvj +aiui

bi, ujdvi + biajd(1

ujvi, uj)+

bivi, bjdvj + bjbi, vjdvi + bibjd(vi, vj))+= f(

aiui

ui, ajdujuj

+ajuj

ai, ujduiui

+ aiajd(1

uiuj)

aiui

ui, bjdvj + bjai, vjduiui

+ aibjd(1

uiui, vj)

bivi, bjdvj +aiui

bi, ujdvi + biajd(1

ujvi, uj)+

bivi, bjdvj + bjbi, vjdvi + bibjd(vi, vj))+[(aiui

ui,−+ bjui

ui,−dvj + biajvi,−+ bjvi,−dvj)(f)

](aj

dujuj

+ bjdvj)

= f [ωi, ωj ] + (ρω(ωi)(f))ωj .

♦ù réstt

Page 139: Structures de Poisson logarithmiques: invariants

♥♥①

s ♣♦♥ts s qqs

s

♥tr♦t♦♥

t ♥♥① ♦r♥t qq éts sr s ♣♦♥ts s rt♥s ♥ ér

♥♦t♠♠♥t ♥♦t♦♥ étté ér♥t ♦♥strt ♣tr

s strtr f, g = xyzdf ∧ dg ∧ dp

dx ∧ dy ∧ dz

♥s s ♥♦s ♥♦s ♦♥♥♦♥s ♥ ♣♦②♥ô♠ ♥♦♥ ♦♥st♥t p ♥s A = C[x, y, z] râ

q ♥♦s é♥ss♦♥s r♦t P♦ss♦♥ ♦rt♠q s♥t

f, g = hdf ∧ dg ∧ dpdx ∧ dy ∧ dz

P♦r ér s ♥♦tt♦♥s ♥♦s ♦♥sér♦♥s s s♦♠♦r♣s♠s s♥ts

Ω1A(logD)

ϕ1−→ A3 ∼= A×A×Af1dx

x+ f2

dy

y+ f3

dz

z7→ (f1, f2, f3)

Ω2A(logD)

ϕ2−→ A3 ∼= A×A×Af1dy

y∧ dz

z+ f2

dz

z∧ dx

x+ f3

dx

x∧ dy

y7→ (f1, f2, f3)

Ω3A(logD)

ϕ2−→ Afdx

x∧ dy

y∧ dz

z7→ f

∧1DerA(logD)ψ1−→ A3 ∼= A×A×A

f1x∂x+ f2y∂y + f3z∂z 7→ (f1, f2, f3)

∧2DerA(logD)ψ2−→ A3 ∼= A×A×A

f1y∂y ∧ z∂z + f2z∂z ∧ x∂x+ f3x∂x ∧ y∂y 7→ (f1, f2, f3)

∧3DerA(logD)ψ3−→ A

fx∂x ∧ y∂y ∧ z∂z 7→ f

râ à s s♦♠♦r♣s♠s s ♦♣értrs é♥s ♣r éqt♦♥ ♥♥♥t

∂0f = ∂xh(∂yf∂zp− ∂zf∂yp)x∂x + ∂yh(∂zf∂xp− ∂xf∂zp)y∂y+

∂zh(∂xf∂yp− ∂yf∂xp)z∂z

Page 140: Structures de Poisson logarithmiques: invariants

♥♥① s ♣♦♥ts s qqs s

P♦r t♦t f ∈ A,

∂1 ~f =

∂yh(∂zf3∂xp− ∂xf3∂zp)− ∂zh(∂xf2∂yp− ∂yf2∂xp)

−f1x2∂2xxp− f2xy∂2xyp− f3xz∂

2xzp− f1x∂xp

∂zh(∂xf1∂yp− ∂yf1∂xp)− ∂xh(∂yf3∂zp− ∂zf3∂yp)

−f1xy∂2xyp− f2y2∂2yyp− f3yz∂

2yzp− f2y∂yp

∂xh(∂yf2∂zp− ∂zf2∂yp)− ∂yh(∂zf1∂xp− ∂xf1∂zp)

−f1xz∂2xzp− f2yz∂2yzp− f3z

2∂2zzp− f3z∂zp

P♦r t♦t ~f ∈ A3 t ♥ ♥

∂2 ~f = ∂xh(∂yf1∂zp− ∂zf1∂yp) + ∂yh(∂zf2∂xp− ∂xf2∂zp)+

∂zh(∂xf3∂yp− ∂yf3∂xp)

P♦r t♦t ~f ∈ A3. P♦s♦♥s Pi : A3 → A ♣r♦t♦♥ sr iè♠ ♦♠♣♦s♥t

♦♥tr♦♥s q ∂1 ∂0 = 0

♦t f ∈ A.

∂0(f) =

f1 = z∂zpy∂yf − y∂ypz∂zf

f2 = x∂xpz∂zf − z∂zpx∂xf

f3 = y∂ypx∂xf − x∂xpy∂yf

♣rès ♣r♠èr ♦♠♣♦s♥t p1(∂1(∂0(f))) st ♦♥♥é ♣r

P1(∂1(∂0(f))) = ∂yh(∂zf3∂xp− ∂xf3∂zp)− ∂zh(∂xf2∂yp− ∂yf2∂xp)

−f1x2∂2xxp− f2xy∂2xyp− f3xz∂

2xzp− f1x∂xp

♥ sstt♥t f1, f2, f3 ♣r rs ①♣rss♦♥s sss ♦♥ ♦t♥tP1(∂1(∂0(f))) = x2zy∂xp∂xf∂

2yzp+ x2yz∂xp∂yp∂

2xzf − x2yz∂xp∂yf∂

2zxp− x2yz(∂xp)

2∂2zyf−x2yz∂zp∂xf∂

2xyp− x2yz∂zp∂yp∂

2xxf − xzy∂zp∂yp∂xf + x2yz∂zp∂yf∂

2xxp+ x2yz∂zp∂xp∂

2xyf+

xyz∂zp∂xp∂yf − x2yz∂yp∂zf∂2xxp− x2yz∂yp∂xp∂

2xzf − xyz∂yp∂xp∂zf + x2yz∂yp∂xf∂

2xzp+

x2yz∂yp∂zp∂2xxf + xyz∂yp∂zp∂xf + x2yz∂xp∂zf∂

2xyp+ x2yz(∂xp)

2∂2yzf − x2yz∂xp∂xf∂2yz−

x2yz∂xp∂zp∂2yxf − x2z∂zp∂yf∂

2xxp+ x2yz∂yp∂zf∂

2xxp− x2yz∂xp∂zf∂

2xyp+ x2yz∂zp∂xf∂

2xyp

−x2yz∂yp∂xf∂2xzp+ x2yz∂xp∂yf∂2xzp− xyz∂zp∂yf∂xp+ xyz∂yp∂zf∂xp

= 0 ç♦♥ ♥♦ ♦♥ ♠♦♥tr q s trs ♦♠♣♦s♥ts s♦♥t t♦ts ♥s

♦♥tr♦♥s q ∂2 ∂1 = 0

P♦r ér s s t tr tr ♦♥ ♣♦s ♣♦r t♦t ~f =

(f1, f2, f3); (F1, F2, F3) = ~F = ∂1(~f).

♦rs ∂1 ~f =

F1 = ∂yh(∂zf3∂xp− ∂xf3∂zp)− ∂zh(∂xf2∂yp− ∂yf2∂xp)

−f1x2∂2xxp− f2xy∂2xyp− f3xz∂

2xzp− f1x∂xp

F2 = ∂zh(∂xf1∂yp− ∂yf1∂xp)− ∂xh(∂yf3∂zp− ∂zf3∂yp)

−f1xy∂2xyp− f2y2∂2yyp− f3yz∂

2yzp− f2y∂yp

F3 = ∂xh(∂yf2∂zp− ∂zf2∂yp)− ∂yh(∂zf1∂xp− ∂xf1∂zp)

−f1xz∂2xzp− f2yz∂2yzp− f3z

2∂2zzp− f3z∂zpP♦s♦♥s ♥♥

δ1 = −∼−→A 1; δ2 = −

∼−→A 2; δ3 = −

∼−→A 3

♣rès ♦♥ r ∂2(~F ) = δ1(F1) + δ2(F2) + δ3(F3) ♦rs

Page 141: Structures de Poisson logarithmiques: invariants

s strtr P♦ss♦♥ x, y = x.

F1 = δ2(f3)− δ3(f2)− f1x2∂2xxp− f2xy∂

2xyp− f3xz∂

2xzp− f1x∂xp

F2 = δ3(f1)− δ1(f3)− f1xy∂2yxp− f2y

2∂2yyp− f3yz∂2yzp− f2y∂yp

F3 = δ1(f2)− δ2(f1)− f1xz∂2zxp− f2yz∂

2zyp− f3z

2∂2zzp− f3z∂zpt ♦♥

∂2(~F ) =

δ1 δ2(f3)− δ1 δ3(f2)− δ1(f1x2∂2xxp)− δ1(f2xy∂

2xyp)− δ1(f3xz∂

2xzp)− δ1(f1x∂xp)+

δ2 δ3(f1)− δ2 δ1(f3)− δ2(f1xy∂2yxp)− δ2(f2y

2∂2yyp)− δ2(f3yz∂2yzp)− δ2(f2y∂yp)+

δ3 δ1(f2)− δ3 δ2(f1)− δ3(f1xz∂2zxp)− δ3(f2yz∂

2zyp)− δ3(f3z

2∂2zzp)− δ3(f3z∂zp)+ st ♦♥ r q tr♠ tt ①♣rss♦♥ t érr q♦♥ ♦t♥t

t♠♥t ③ér♦ ♦t t ♦♥ ♦t♥t

δ1 δ2(f3) = xyz2(∂zp∂2xyp∂z + ∂zp∂xp∂

2yz − ∂yp∂

2xzp∂z − ∂yp∂xp∂

2zz − ∂zp∂

2yzp∂x

−(∂zp)2∂2yx + ∂yp∂

2zzp∂x + ∂yp∂zp∂

2xz)f3 + xyz(∂yp∂zp∂x − ∂yp∂xp∂z)f3

δ2 δ1(f3) = xyz2(∂xp∂2zzp∂y + ∂zp∂

2xyp∂z − ∂xp∂yp∂2zz − ∂zp∂

2xzp∂y − ∂xp∂

2yzp∂z

−(∂zp)2∂2yx + ∂zp∂yp∂

2zx − ∂zp∂xp∂

2yz)f3 + xyz(∂xp∂zp∂y − ∂xp∂yp∂z)f3

δ1 δ3(f2) = xy2z(∂zp∂2yyp∂x + ∂zp∂yp∂

2yx + ∂yp∂

2xzp∂y + ∂yp∂xp∂

2yz − ∂y∂

2yzp∂x

−(∂yp)2∂2xz − ∂zp∂

2xyp∂y − ∂zp∂xp∂

2yy)f2 + xyz(∂zp∂yp∂x − ∂zp∂xp∂y)f2

δ3 δ1(f2) = xy2z(∂yp∂2xzp∂y + ∂yp∂zp∂

2yx + ∂xp∂

2yyp∂z + ∂xp∂yp∂

2yz − ∂x∂

2yzp∂y

−(∂yp)2∂2xz − ∂yp∂

2xyp∂z − ∂xp∂zp∂

2yy)f2 + xyz(∂xp∂yp∂z − ∂xp∂zp∂y)f2

δ2 δ3(f1) = x2yz(∂xp∂2zyp∂x + ∂xp∂yp∂

2xz + ∂zp∂xp∂

2xy + ∂zp∂

2xxp∂y − ∂xp∂

2xzp∂y

−(∂xp)2∂2yz − ∂zp∂yp∂

2xx − ∂zp∂

2yxp∂x)f1 + xyz(∂zp∂xp∂yp− ∂zp∂yp∂x)f1

δ3 δ2(f1) = x2yz(∂yp∂2xxp∂z + ∂yp∂xp∂

2xz + ∂xp∂zp∂

2xy + ∂xp∂

2yzp∂x − ∂xp∂

2xyp∂z

−(∂xp)2∂2yz − ∂yp∂zp∂

2xx − ∂yp∂

2zxp∂x)f1 + xyz(∂yp∂xp∂zp− ∂yp∂zp∂x)f1

−δ1(f1x∂x(x∂xp)) = −xyz∂zp∂yf1∂xp− x2yz∂yf1∂2xxp+ xyz∂yp∂zf1∂xp+

x2yz∂yp∂zf1∂2xxp− f1xyz∂zp∂

2xyp− f1x

2yz∂wp∂3xxyp+ f1xyz∂yp∂

2xzp+

f1x2yz∂yp∂

3xxzp

−δ1(f2xy∂2xyp) = −xy2z∂zp∂2xyf2 + xy2z∂yp∂2xyp∂zf2 − f2xyz∂zp∂

2xyp

−f2xy2z∂zp∂3xyyp+ f2xy2z∂yp∂

2xyzp

−δ1(f3xz∂2xzp) = −xz2y∂zp∂yf3∂2xzf2 + xz2y∂yp∂2xzp∂zf3 − f3xyz

2∂zp∂3xyzp

−f3xz2y∂yp∂3xzzp+ f3xyz∂yp∂2xzp

−δ2(f2y∂y(y∂yp)) = −xyz2∂xp∂yp∂zf2 + xyz∂zp∂yp∂xf2 − xy2z∂xp∂zf2∂2yyp

+xy2z∂zp∂xf2∂2yyp− f2xyz∂xp∂

2yzp+ f2xyz∂zp∂

2xyp− f2xy

2z∂xp∂yyzp+ f2xy2z∂zp∂

3xyyp

−δ2(f1xy∂2xyp) = −yx2z∂xp∂zf1∂2xyp+ yx2z∂zp∂2xyp∂xf1 − f1x

2yz∂xp∂3xyzp

+f1x2yz∂zp∂

3xxyp+ f1xyz∂zp∂

2xyp

−δ2(f3zy∂2zyp) = −xz2y∂xp∂2zyf3 + xz2y∂zp∂2zyp∂xf3 − f3xyz

2∂xp∂3yzzp

−f3xyz∂xp∂2zyp+ f3xz2y∂zp∂

3xyzp

−δ3(f3z∂z(z∂zp)) = −xyz∂yp∂zp∂xf3 − xyz2∂yp∂xf3∂2zzp+ xyz∂xp∂yf3∂zp

+xyz2∂xp∂yf3∂2zzp− f3xyz∂yp∂

2xzp− f3xyz

2∂yp∂2xzzp+ f3xyz∂xp∂

2yzp+ f3xyz

2∂xp∂3yzzp

−δ3(f1xz∂2xzp) = −x2yz∂yp∂xf1∂2xyp+ x2yz∂xp∂2xzp∂yf1 − f1x

2yz∂yp∂3xyxp

−f1xyz∂yp∂2xzp+ f1x2yz∂xp∂

3xyzp

−δ3(f2yz∂2yzp) = −y2xz∂yp∂xf2∂2zyp+ xy2z∂xp∂2yzp∂yf2 − f2xy

2z∂yp∂3xyzp

+f2xy2z∂xp∂

3yyzp+ f2xyz∂xp∂

2yzp

s strtr P♦ss♦♥ x, y = x.

♥s t ♥♥① ♥♦s ♥♦s ♣r♦♣♦s♦♥s érr sr ①♠♣ x, y = x tté

strtr èr ♥rt sr ΩA(log xA).

s éé♠♥ts ♠♦ ΩA(log xA) s♦♥t s♦s ♦r♠ αdx

x+ βdy ♦ù α, β ∈ A.

Page 142: Structures de Poisson logarithmiques: invariants

♥♥① s ♣♦♥ts s qqs s

♦♥t α1 = α01

dx

x+ α1

1dy, α2 = α02

dx

x+ α1

2dy, α3 = α03

dx

x+ α1

3dy tr♦s éé♠♥ts

ΩA(log xA).

♦rs

[α1, α2] = [α01

dx

x, α0

2

dx

x] + [α0

1

dx

x, α1

2dy] + [α11dy, α

02

dx

x] + [α1

1dy, α12dy].

r [α01

dx

x, α0

2

dx

x] = (α0

1∂yα02 − α0

2∂yα01)dx

x, [α0

1

dx

x, α1

2dy] = xα12∂xα

01

dx

x+ α0

1∂yα12dy,

[α11dy, α

02

dx

x] = −xα1

1∂xα02

dx

x− α0

2∂yα11dy, [α

11dy, α

12dy] = (xα1

2∂xα11 − xα1

1∂xα12)dy

s♥st q

[α1, α2] = (α01∂yα

02 − α0

2∂yα01 + xα1

2∂xα01 − xα1

1∂xα02)dx

x+ (α0

1∂yα12 − α0

2∂yα11 + xα1

2∂xα11 −

xα11∂xα

12)dy

P♦s♦♥s α = α01∂yα

02 −α0

2∂yα01 + xα1

2∂xα01 − xα1

1∂xα02 t β = α0

1∂yα12 −α0

2∂yα11 + xα1

2∂xα11 −

xα11∂xα

12.

♥ ♦rs

[[α1, α2], α3] = [αdx

x+ βdy, α0

3

dx

x+ α1

3dy]

= [αdx

x, α0

3

dx

x] + [α

dx

x, α1

3dy] + [βdy, α03

dx

x] + [βdy, α1

3dy]

r

[αdx

x, α0

3

dx

x] = (α∂yα

03 − α0

3∂yα)dx

x, [α

dx

x, α1

3dy] = xα13∂xα

dx

x+ α∂yα

13dy,

[βdy, α03

dx

x] = −xβ∂xα0

3

dx

x− α0

3∂yβdy, [βdy, α13dy] = (xα1

3∂xβ − xβ∂xα13)dy.

♦♥

[[α1, α2], α3] = (α∂yα03 − α0

3∂yα + xα13∂xα + xβ∂xα

03)dx

x+ (α∂yα

13 − α0

3∂yβ + xα13∂xβ −

xβ∂xα13)dy.

♥ ♦♥sèr s ♣♣t♦♥s Pi : ΩA(log xA) → A é♥s ♣r

P1(adx

x+ bdy) = a t P2(a

dx

x+ bdy)) = b t ♦♥ ♣♦s

A123 := P1([[α1, α2], α3]), A231 := P1([[α2, α3], α1]) t A312 := P1([[α3, α1], α2]).

Pr rs s ♥♦s ♣♦s♦♥s B123 := P2([[α1, α2], α3]), B231 := P2([[α2, α3], α1]) t

B312 := P2([[α3, α1], α2]),

♦rs

A123 = α∂yα03 −α0

3∂yα+ xα13∂xα+ xβ∂xα

03 t B123 = α∂yα

13 −α0

3∂yβ + xα13∂xβ − xβ∂xα

13.

Pr rs∂y(α) = ∂y(α

01∂yα

02 − α0

2∂yα01 + xα1

2∂xα01 − xα1

1∂xα02)

= ∂yα01∂yα

02 + α0

1∂2yyα

02 − ∂yα

02∂yα

01 − α0

2∂2yyα

01 + x∂yα

12∂xα

01+

xα12∂

2yxα

01 − x∂yα

11∂xα

02 − xα1

1∂2xyα

02

∂xα = ∂x(α01∂yα

02 − α0

2∂yα01 + xα1

2∂xα01 − xα1

1∂xα02)

= ∂xα01∂yα

02 + α0

1∂2xyα

02 − ∂xα

02∂yα

01 − α0

2∂2xyα

01 + α1

2∂xα01 + x∂xα

12∂xα

01 + xα1

2∂2xxα

01

−α11∂xα

02 − x∂xα

11∂xα

02 − xα1

1∂2xxα

02

Page 143: Structures de Poisson logarithmiques: invariants

s strtr P♦ss♦♥ x, y = x.

♥ ♦t♥t ♦♥

A123 = α01∂yα

02∂yα

03 − α0

2∂yα01∂yα

03 + xα1

2∂xα01∂yα

03 − xα1

1∂xα02∂yα

03 − α0

3∂yα01∂yα

02

−α03α

01∂

2yyα

02 + α0

3∂yα02∂yα

01 + α0

3α02α

2yyα

01 − xα0

3∂yα12∂xα

01 − xα0

3α12∂

2yxα

01 + xα0

3∂yα11∂xα

02+

xα03α

11∂

2xyα

02 ++xα1

3∂xα01∂yα

02 + xα1

3α01∂

2xyα

02 − xα1

3∂xα02∂yα

01 − xα1

3α02∂

2xyα

01 + xα1

3α12∂xα

01+

x2α13∂xα

12∂xα

01 + x2α1

3α12∂

2xxα

01 − xα1

3α11∂xα

02 − x2α1

3∂xα11∂xα

02 − x2α1

3α11∂

2xxα

02 − xα0

1∂yα12∂xα

03+

xα02∂yα

11∂xα

03 + x2α1

1∂xα12∂xα

03 − x2α1

2∂xα11∂xα

03

A231 = α02∂yα

03∂yα

01 − α0

3∂yα02∂yα

01 + xα1

3∂xα02∂yα

01 − xα1

2∂xα03∂yα

01 − α0

1∂yα02∂yα

03

−α01α

02∂

2yyα

03 + α0

1∂yα03∂yα

02 + α0

1α03∂

2yyα

02 − xα0

1∂yα13∂xα

02 − xα0

1α13∂

2yxα

02 + xα0

1∂yα12∂xα

03+

xα01α

12∂

2xyα

03 ++xα1

1∂xα02∂yα

03 + xα1

1α02∂

2xyα

03 − xα1

1∂xα03∂yα

02 − xα1

1α03∂

2xyα

02 + xα1

1α13∂xα

02+

x2α11∂xα

13∂xα

02 + x2α1

1α13∂

2xxα

02 − xα1

1α12∂xα

03 − x2α1

1∂xα12∂xα

03 − x2α1

1α12∂

2xxα

03 − xα0

2∂yα13∂xα

01+

xα03∂yα

12∂xα

01 + x2α1

2∂xα13∂xα

01 − x2α1

3∂xα12∂xα

01

A312 = α03∂yα

01∂yα

02 − α0

1∂yα03∂yα

02 + xα1

1∂xα03∂yα

02 − xα1

3∂xα01∂yα

02 − α0

2∂yα03∂yα

01

−α02α

03∂

2yyα

01 + α0

2∂yα01∂yα

03 + α0

2α01∂

2yyα

03 − xα0

2∂yα11∂xα

03 − xα0

2α11∂

2yxα

03 + xα0

2∂yα13∂xα

01+

xα02α

13∂

2xyα

01 ++xα1

2∂xα03∂yα

01 + xα1

2α03∂

2xyα

01 − xα1

2∂xα01∂yα

03 − xα1

2α01∂

2xyα

03 + xα1

2α11∂xα

03+

x2α12∂xα

11∂xα

03 + x2α1

2α11∂

2xxα

03 − xα1

2α13∂xα

01 − x2α1

2∂xα13∂xα

01 − x2α1

2α13∂

2xxα

01 − xα0

3∂yα11∂xα

02+

xα01∂yα

13∂xα

02 + x2α1

3∂xα11∂xα

02 − x2α1

1∂xα13∂xα

02

♦ù A123 +A231 +A312 = 0

P♦r ♠♦♥trr qB123+B231+B312 = 0 ♦♥ ♣t ♣r♦ér ♦♠♠ sss ♥ r♠♣ç♥t

α t β ♣r rs ①♣rss♦♥s rs♣ts ♦s ♦♥s ♣r♦ér tr♠♥t é st tsr

♥tté ♦ strtr P♦ss♦♥ s♦♥t

♠rq♦♥s q

[[α1, α2], α3] = [[α01

dx

x, α0

2

dx

x], α0

3

dx

x] + [[α0

1

dx

x, α0

2

dx

x], α1

3dy] + [[α01

dx

x, α1

2dy], α03

dx

x] +

[[α01

dx

x, α1

2dy], α13dy] + [[α1

1dy, α02

dx

x], α0

3

dx

x] + [[α1

1dy, α02

dx

x], α1

3dy]

[[α11dy, α

12dy], α

03

dx

x] + [[α1

1dy, α12dy], α

13dy]

♥ ♥st ♠♠ s♥t

♠♠ s ♥♦tt♦♥s sss ♦♥

[[α01

dx

x, α0

2

dx

x]+ = 0

[[α11dy, α

12dy], α

13dy]+ = 0

Pr

P♦r q st ♣r♠èr été ♦♥

Page 144: Structures de Poisson logarithmiques: invariants

♥♥① s ♣♦♥ts s qqs s

[[α01

dx

x, α0

2

dx

x]+ =

= ( 1x(α0

1

xx, α0

2+α0

2

xα0

1, x)x, α03+

α0

3

0

1

xx, α0

2+α0

2

xα0

1, x, x)dx

x= ( 1

x(α0

1

xx, α0

2x, α03+

α0

2

xα0

1, xx, α03) +

α0

3

xx, α0

2α0

1

x, x+ α0

3

x

α0

1

xx, α0

2, x+α0

3

xα0

1, xα0

2

x, x+ α0

3

x

α0

2

xα0

1, x, x)dx

x+

= ( 1x(α0

1

xx, α0

2x, α03+

α0

2

xα0

1, xx, α03) +

α0

3

x2 x, α02α0

1, x −α0

3

x

α0

1

x2 x, α01x, x+

α0

3

x

α0

1

xx, α0

2, x+α0

3

x2 α01, xα0

2, x −α0

3

x

α0

2

x2 α01, xx, x+

α0

2

x

α0

3

xα0

1, x, x)dx

x+

= ( 1x(α0

1

xx, α0

2x, α03+

α0

2

xα0

1, xx, α03) +

α0

3

x

α0

1

xx, α0

2, x+α0

2

x

α0

3

xα0

1, x, x)dx

x+

= (α0

1

x2 x, α02x, α0

3+α0

2

x2 α01, xx, α0

3+α0

3

x

α0

1

xx, α0

2, x+α0

2

x

α0

3

xα0

1, x, xα0

2

x2 x, α03x, α0

1+α0

3

x2 α02, xx, α0

1+α0

1

x

α0

2

xx, α0

3, x+α0

3

x

α0

1

xα0

2, x, xα0

3

x2 x, α01x, α0

2+α0

1

x2 α03, xx, α0

2+α0

2

x

α0

3

xx, α0

1, x+α0

1

x

α0

2

xα0

3, x, x)dx

x= 0

P♦r q st ♦♥ [[α1

1dy, α12dy], α

13dy]+ =

= [(α11y, α1

2+ α12α1

1, y)dy, α13dy]+

= (α11y, α1

2+ α12α1

1, y)y, α13+ α1

3α11y, α1

2+ α12α1

1, y, y)dy+

= (α11y, α1

2y, α13+ α1

2α11, yy, α1

3+ α13α

11y, α1

2, y+ α13α

12α1

1, y, yα13y, α1

2α11, y+ α1

3α11, yα1

2, y +

α12y, α1

3y, α11+ α1

3α12, yy, α1

1+ α11α

12y, α1

3, y+ α11α

13α1

2, y, yα11y, α1

3α12, y+ α1

1α12, yα1

3, y +

α13y, α1

1y, α12+ α1

1α13, yy, α1

2+ α12α

13y, α1

1, y+ α12α

11α1

3, y, yα12y, α1

1α13, y+ α1

2α13, yα1

1, y)dy= 0

s♥st q s ♦♥ts dy rst♥t ♣r♦♥♥♥t

[[α01

dx

x, α0

2

dx

x], α1

3dy]+[[α01

dx

x, α1

2dy], α03

dx

x]+[[α0

1

dx

x, α1

2dy], α13dy]+[[α1

1dy, α02

dx

x], α0

3

dx

x]+

[[α11dy, α

02

dx

x], α1

3dy] + [[α11dy, α

12dy], α

03

dx

x]

P♦r tr♠♥r st ♠♦♥trr q s r♥èrs s♦♥t ♥s P♦r ♣r♦♦♥s

♠♠ s♥t

♠♠ ♦t 〈−,−〉 r♦t té DerA(log xA) = Ω∗A(log xA). ♦rs

〈[[α01

dx

x, α0

2

dx

x], α1

3dy] + [[α01

dx

x, α1

2dy], α03

dx

x] + [[α1

1dy, α02

dx

x], α0

3

dx

x], ∂y〉+ = 0

〈[[α01

dx

x, α1

2dy], α13dy] + [[α1

1dy, α02

dx

x], α1

3dy] + [[α11dy, α

12dy], α

03

dx

x], ∂y〉+ = 0

Pr

P♦r q st ♥♦s ♦♥s

〈[[α01

dx

x, α0

2

dx

x], α1

3dy] + [[α01

dx

x, α1

2dy], α03

dx

x] + [[α1

1dy, α02

dx

x], α0

3

dx

x], ∂y〉+ =

=α0

1

x2 x, α02x, α1

3+α0

2

x2 α01, xx, α1

3+α0

3

x

α0

1

xx, α1

2, x+α0

3

x2 x, α12α0

1, x+α0

3

x

α0

2

xα1

1, x, x+α0

3

x2 α11, xα0

2, x +α0

2

x2 x, α03x, α1

1+α0

3

x2 α02, xx, α1

1+α0

1

x

α0

2

xx, α1

3, x+α0

1

x2 x, α13α0

2, x+α0

1

x

α0

3

xα1

2, x, x+α0

1

x2 α12, xα0

3, x +α0

3

x2 x, α01x, α1

2+α0

1

x2 α03, xx, α1

2+α0

2

x

α0

3

xx, α1

1, x+α0

2

x2 x, α11α0

3, x+α0

2

x

α0

1

xα1

3, x, x+α0

2

x2 α13, xα0

1, x +

Page 145: Structures de Poisson logarithmiques: invariants

s strtr P♦ss♦♥ x, y = x.

♥t à ♦♥

〈[[α01

dx

x, α1

2dy], α13dy] + [[α1

1dy, α02

dx

x], α1

3dy] + [[α11dy, α

12dy], α

03

dx

x], ∂y〉+

=α0

1

xx, α1

2y, α13+

α1

2

xα0

1, yx, α13+

α1

3α0

1

xx, α1

2, y+α1

3

xx, α1

2α01, y+

−α1

3α0

1

x2 x, α12x, y+

α1

1

xy, α0

2x, α13+

α0

2

xα1

1, xy, α13+

α1

3α0

2

xα1

1, x, y+α1

3

xα1

1, xα02, y −

α1

3α0

2

x2 α11, xx, y+

α0

3α1

1

xy, α1

2, x+α0

3

xy, α1

2α11, x+

α0

3α1

2

xα1

1, y, x+α0

3

xα1

1, yα12, x

α0

2

xx, α1

3y, α11+

α1

3

xα0

2, yx, α11+

α1

1α0

2

xx, α1

3, y+α1

1

xx, α1

3α02, y+

−α1

1α0

2

x2 x, α13x, y+

α1

2

xy, α0

3x, α11+

α0

3

xα1

2, xy, α11+

α1

1α0

3

xα1

2, x, y+α1

1

xα1

2, xα03, y −

α1

1α0

3

x2 α12, xx, y+

α0

1α1

2

xy, α1

3, x+α0

1

xy, α1

3α12, x+

α0

1α1

3

xα1

2, y, x+α0

1

xα1

2, yα13, x

α0

3

xx, α1

1y, α12+

α1

1

xα0

3, yx, α12+

α1

2α0

3

xx, α1

1, y+α1

2

xx, α1

1α03, y+

−α1

2α0

3

x2 x, α11x, y+

α1

3

xy, α0

1x, α12+

α0

1

xα1

3, xy, α12+

α1

2α0

1

xα1

3, x, y+α1

2

xα1

3, xα01, y −

α1

2α0

1

x2 α13, xx, y+

α0

2α1

3

xy, α1

1, x+α0

2

xy, α1

1α13, x+

α0

2α1

1

xα1

3, y, x+α0

2

xα1

3, yα11, x

= 0

♠♥èr ♥♦ ♦♥ ♣r♦

Page 146: Structures de Poisson logarithmiques: invariants
Page 147: Structures de Poisson logarithmiques: invariants

♦r♣

❬ss② t ❪ ♠tr ss② Ptr ❲ ♦r t ❲♦♥ ♣♣rt ①

t♥s♦♥ ♦ rs r♥ r♦♥r ♥sttt t t♠ts P②s ♦t③

♠♥♥ss té ♥ ♣

❬t② t♥ ❪ r♥s t② t t♥ ♦♠tr② ♥ ②

♥♠s ♦ ♠♥t ♠♦♥♦♣♦s Pr♥t♦♥ ❯♥rst② Prss P♦rtr

trs té ♥ ♣

❬r ❪ P r ♣r♥♣s ♦ q♥t♠ ♠♥s ①♦r ❯♥rst② Prss

té ♥ ♣s t

❬♦♥s♦♥ ❪ ♠♦♥ r♥ ♦♥s♦♥ ♠s qt♦♥s ♥ t sst♦♥ ♦

♠♦♥♦♣♦s ♦♠♠♥ t P②s ♦ ♣s té ♥ ♣

❬♦♥♦ ❪ ♦s♣ ♦♥♦ ♦rt♠ P♦ss♦♥ ♦♦♠♦♦② ①♠♣ ♦ t♦♥

♥ ♣♣t♦♥ t♦ ♣rq♥t③t♦♥ ❳ ♣t ♥r té

♥ ♣

❬♦t♦ ❪ ②s ♦t♦ ♦③♥s②❲tt♥ ♥r♥ts ♦ ♦ ②♠♣t ♥♦s ♦♥

t♠♣♦rr② t♠ts ♦ ♣s té ♥ ♣s t

❬♦ss t ❪ ♦ss rtr♠ ♦st♥t t ① ♦s♥r r♥t

♦r♠s ♥ r ♥ rs r♥s ♠r t ♦ ♦ ♥♦ ♣s

rs té ♥ ♣

❬s♠♥♥ ❪ ♦♥♥s s♠♥♥ P♦ss♦♥ ♦♦♠♦♦② ♥ q♥t③t♦♥

♥ ♥ t ♦ ♣s té ♥ ♣s t

❬♦r♦s♥ t ❪ ♦r♦s♥ t ❱ ts♦ ♠② ♦ P♦ss♦♥

strtrs ♦♥ r♠t♥ s②♠♠tr s♣s té ♥ ♣s t

❬♦st♥t ❪ rtr♠ ♦st♥t ♥t③t♦♥ ♥ ♥tr② r♣rs♥tt♦♥ Prt Pr

q♥t③t♦♥ tr ♥ ♠♦r♥ ♥②ss ♥ ♣♣t♦♥ ♣s ♣

té ♥ ♣

❬♦t♦ ❪ ①② ♦t♦ ♠rs ♦♥ ♦♠tr ♥t③t♦♥ ♦ ♠tr① ②♣ P♦ss♦♥

rts ♦rt t ③ té ♥ ♣

❬rss ❪ rss ♦t♥ rt ♥ ♥♦♥ rs t

♦ts t ♥♦ ♣s té ♥ ♣s t

❬♥r♦③ ❪ ♥r♦③ s rétés P♦ss♦♥ t rs èrs s

s♦és ♦♠ ♦ ♣s té ♥ ♣

❬♦t♦ ❪ ♦t♦ rs ♦r♠r ♦r r♥ sss ss♦t t ♦rt♠

♦♥♥t♦♥s ♦②♦ té ♥ ♣

❬t♦ ❪ r♥♦ t♦ ♦ ♣ ♦r ♦♦♥♦♠ ②st♠ P ②♦t♦ ❯♥

♦ ♥♦ ♣s ♠ té ♥ ♣s t

❬P♦s ❪ ♠ P♦s r ♦♠tr② ♦ P♦ss♦♥ rts ♦r♥ ♦

t♠t ♥s ♦ ♥♦ té ♥ ♣s t

❬♥rt ❪ ♥rt r♥t ♦r♠s ♦r ♥r ♦♠♠tt rs r♥s

♠r t ♦ ♦ ♣s té ♥ ♣

❬t♦ ❪ ②♦ t♦ ♦r② ♦ ♦rt♠ r♥t ♦r♠s ♥ ♦rt♠ t♦r

s ❯♥ ♦②♦ ♦ ♣s té ♥

♣s t

Page 148: Structures de Poisson logarithmiques: invariants

♦r♣

❬♦r ❪ ♦r trtr s s②stè♠s ②♥♠qs ♥♦ té ♥

❬r ❱rr ❪ r♠♥♦ r t ♥♦s ❱rr ❱rétés rt

rs s s♦t♦♥s ♣tqs P Pr♦♥s ♦ t ♥♦r♥ ♦♥r♥ ♦♥

♦♠tr② ♦♠② ♥st♥ ♦♦ ♥② ♣s

té ♥ ♣

❬❯r♥ ❪ ❲ ❯r♥ ♣rq♥t③t♦♥ ♣rs♥tt♦♥ ♦ P♦ss♦♥ r

♥ t ♦ ♣s té ♥ ♣s t

❬❱♥♦r♦ ❪ ❱♥♦r♦ ♦ r ♦ ♥r rt ♦♣rt♦rs

♦t t ♦ ♦ ♣s té ♥ ♣

Page 149: Structures de Poisson logarithmiques: invariants

és♠é ♦t tt tès st ♣r♦♣♦sr s rtèrs ♣réq♥tt♦♥ s

strtrs P♦ss♦♥ à s♥rtés ♣♦rtés ♣r ♥ sr r ♥ rété ♦♠♣①

♠♥s♦♥ ♥

P♦r ♥♦s ♣rt♦♥s ♥ ♦♥strt♦♥ érq s ér♥ts ♦r♠s ♦rt

♠qs ♦♥ ♥ é ♥♠♥t ♥♥ré t ♣r♦♣r ♥ èr ♦♠♠tt ♣♦r

♥tr♦r ♥♦t♦♥ èr P♦ss♦♥ ♦rt♠q Ps ♥♦s ♠♦♥tr♦♥s q ts

strtrs P♦ss♦♥ ♥s♥t ♥ ♥♦ ♥r♥t ♦♦♠♦♦q ♣r t ♥

strtr èr ♥rt qs ♥s♥t sr ♠♦ s ér♥ts

♦r♠s ♦rt♠qs râ à r♥r ♥♦s ét♦♥s s ♦♥t♦♥s ♥térté s

ts strtrs P♦ss♦♥

♦t ♦r ♥♦s ♠♦♥tr♦♥s q ♣♣t♦♥ ♠t♦♥♥♥ t♦t strtr P♦ss♦♥

♦rt♠q s ♣r♦♦♥ sr ♠♦ s ér♥ts ♦r♠s ♦rt♠qs t

♥t ♥ strtr èr ♥rt sr r♥r ♣s ♠ tt

♣♣t♦♥ st ♦♥t♥ ♥s ♠♦ s ért♦♥s ♦rt♠qs ♦s ♣♣♦♥s

♦♦♠♦♦ P♦ss♦♥ ♦rt♠q ♦♦♠♦♦ ♥t ♣r tt r♣rés♥tt♦♥

Pr st ♥♦s ♠♦♥tr♦♥s sr qqs ①♠♣s q s r♦♣s ♦♦♠♦♦s

P♦ss♦♥ t ① P♦ss♦♥ ♦rt♠q s♦♥t ♥ é♥ér ér♥ts ♥ qs ♦ï♥♥t

♥s s s strtrs P♦ss♦♥ ♦s②♠♣tqs

♦s tr♠♥♦♥s ♣r ♥ ét s ♦♥t♦♥s ♥térté ts strtrs ♠♦②♥

tt ♦♦♠♦♦

♦ts és trtrs P♦ss♦♥ ♦♦♠♦♦ P♦ss♦♥ sr r

èr ♥rt q♥tt♦♥ ért♦♥ ♦♥trr♥t ♦rt♠q strtr

♦s②♠♣tq strtr P♦ss♦♥ ♦rt♠qs

Page 150: Structures de Poisson logarithmiques: invariants

strt ♠♥ ♦t ♦ ts tss s t♦ ♣r♦♣♦s rtr ♦ ♣rq♥t③t♦♥ ♦

s♥r P♦ss♦♥ strtrs t s♥rts rr ② r s♦r ♦ ♥t ♠♥s♦♥

♦♠♣① ♠♥♦

♦r ts strt r♦♠ ♥ r ♦♥strt♦♥ ♦ ♦r♠ ♦rt♠ r♥ts ♦♥

♥t② ♥rt ♥♦♥ tr ♦ ♦♠♠tt ♥ ♥tr② r ❲ ♥tr♦

t ♦♥♣t ♦ ♦rt♠ P♦ss♦♥ r ♥ s♦ tt ts P♦ss♦♥ strtrs

♥ ♥ ♦♦♠♦♦ ♥r♥t ts s ♦ t ♥rt r strtr

tt t② ♥ ♦♥ t ♠♦ ♦ ♦r♠ ♦rt♠ r♥ts ❲t t ttr

st② t ♥tr ♦♥t♦♥s ♦ s P♦ss♦♥ strtrs

rst s♦ tt t ♠t♦♥♥ ♠♣ ♦ ♦rt♠ P♦ss♦♥ strtr ①t♥s t♦ t

♠♦ ♦ ♦r♠ ♦rt♠ r♥t ♥ ♥s strtr ♦ ♥rt

r ♦♥ t rtr♠♦r s♦ tt ts ♠ s ♦♥t♥ ♥ t ♠♦ ♦ ♦rt♠

rt♦♥s ❲ ♦rt♠ P♦ss♦♥ ♦♦♠♦♦ t ♦♦♠♦♦ ♥ ② ts

r♣rs♥tt♦♥

sq♥t② s♦ ♦♥ s♦♠ ①♠♣s tt P♦ss♦♥ ♦♦♠♦♦s r♦♣s ♥ P♦ss♦♥

♦rt♠ ♦♦♠♦♦s r♦♣s r r♥t ♥ ♥r t♦ t② ♦♥ ♥ t s

♦ ♦s②♠♣t P♦ss♦♥ strtrs ❲ ♦♥ t st② t ♣rq♥t③t♦♥ ♦♥

t♦♥s ♦ s strtrs ② ♠♥s ♦ ts ♦♦♠♦♦②

②♦rs P♦ss♦♥ strtrs P♦ss♦♥ ♦♦♠♦♦② r s♦r ♥rt r

q♥t③t♦♥ ♦s②♠♣t strtr ♦rt♠ P♦ss♦♥ strtrs ♦rt♠ ♦♥trr

♥t rt♦♥