dark%maer ,...

Dark ma'er, dark energy and par/cle physics

Pierre Binétruy, APC, Paris

Moriond, 24 March 2016

Dark ma'er, dark energy, infla/on, gravita/onal waves, diphoton events… and par/cle physics

Pierre Binétruy, APC, Paris

Moriond, 24 March 2016

2012: discovery of the Higgs par/cle at LHC

2013: release of Planck data

We are certainly living a golden era…

2016: discovery of gravita/onal waves

All 3 of them, a triumph of theore/cal insight and experimental or observa/onal achievement

… which may be not finished

April 22, launch of the Microscope satellite: test of the equivalence principle to the 10-‐15

Jan Stark for the ATLAS collaboration Moriond QCD -- March 19-26, 2016 11

Di-photons: search for spin-0 resonancePerform 2D p

0 scan (as function of mass and width

of the hypothetical resonance).

Largest deviation from background-only hypothesis: near 750 GeV width 45 GeV (i.e. 6%)

Local significance: 3.9σGlobal significance: 2.0σ

Report limits on fiducial cross sectionas a function of mass hypothesis,for several width hypotheses.

Example shown here: width of 6%

ATLAS-CONF-2016-xxx

A new spin-‐0 resonance? First sign of new physics beyond SM Jan Stark, QCD

(GeV)Xm210×5 310 310×2 310×3

0p

-410

-310

-210

-110

-2 10× = 1.4 mΓ

J = 0

J = 2

σ1

σ2

σ3

(13 TeV)-13.3 fbCMS Preliminary

New Physics with light SM particles at CMS – JPC – Rutgers University – Sunday, March 20th, 2016

DIPHOTON RESONANCES

• Limits set on a three different widths• Γ/M=1.4x10-4, 1.4x10-2, 5.6x10-2

• Both spin-0 and spin-2 hypotheses• limits and p-values very similar

9

[EXO-16-018]

(GeV)Sm210×5 310 310×2 310×3

) (fb

)γγ

→ S

→(p

pσ

95%

C.L

. lim

it

02468

10121416182022 J=0-2 10× = 1.4 m

Γ

Expected limitσ 1 ± σ 2 ±

Observed limit


Diphoton limits at 13 TeV (0 and 3.8 T)

(GeV)Sm210×5 210×6 210×7 210×8

0p

-410

-310

-210

-110

J=0-2 10× = 1.4 mΓ

Combined-10T 0.6 fb

-13.8T 2.7 fb

σ1

σ2

σ3


p-values at 13 TeVfor 0T, 3.8T and combination

John Paul Chou, QCD

From the point of view of cosmology, two compelling events in recent years:

2012: discovery of the Higgs par/cle at LHC

2013: release of Planck data

Why? In the early 1980s, the high energy community developed a model of the Primordial Universe based on the Standard Model and its extensions (in par/cular Grand Unifica/on)

This Model led to a common framework for trying to explain:

•  the ma'er-‐an/ma'er asymmetry through fundamental interac/ons

•  the flatness, horizon (and monopole) problems through the scenario of infla/on

poten/al at high T

energy stored typically ρ0∼ MU

4 ∼ (1016 GeV)4

Einstein eqns : Tμν ∼ ρ0 gμν ⟹ H2 = 8πGN ρ0 /3 = cst Hvac2 ⟹ de Si'er solu/on a(t) ∼ exp (Hvact)

A. Linde A. Guth

This Model led to a common framework for trying to explain:

•  the ma'er-‐an/ma'er asymmetry through fundamental interac/ons

•  the flatness, horizon (and monopole) problems through the scenario of infla/on

•  dark ma'er, in the form of par/cles

•  more recently, the accelera/on of the expansion of the Universe, through a new component, dark energy

Note that « fundamental » scalar fields play a central role in this paradigm.

Why?

Scalar fields easily provide a diffuse background

Speed of sound cs2 = (δp / δρ)adiaba/c

In most models, cs2 ~ 1, i.e. the pressure of the scalar field resists gravita/onal clustering :

Unless in specific cases, scalar fields tend not to cluster.

V(φ)

φ

ρφ = φ2 /2 + V(φ) energy density

pφ = φ2 /2 + V(φ) pressure .

.

Planck results: what comforted the infla/on paradigm?

Pre-‐Planck: space.me is spa.ally flat Ω = 1 or ρ = ρc

Planck: ns = 0.968 ±0.006

ns<1, built-‐in instability

ns=1, infla/on for ever (de Si'er)

Rehea/ng: inflaton decay into par/cles slows down oscilla/ons and repopulates the Universe

The discovery of the Higgs has thus provided the first « fundamental » scalar field.

If there is one, why not many?

Indeed, triviality argument

scale

coupling abelian gauge

λφ4

nonabelian gauge

Λ

Note also that the only dimensionful parameter in the Standard Model is the Higgs mass m:

L = -‐ m2 φ+ φ

If it has a dynamical origin, its value should be fixed by another field

For example. another scalar field S L = -‐ η S2 φ+ φ

No/on of Higgs portal:

Or , the space-‐/me curvature R (of dimension L-‐2) L = -‐ R2 φ+ φ

(η: coupling)

(scenario of Higgs infla/on)

VolksModell (the everybody’s model)

The Sgg and S�� operators can be generated if S couples to charged particles

SQ̄f(yf + i y5f�5)Qf + SAsQ̃⇤sQ̃s

g

g

Q

S

Q

g

g

Extra fermions Q or scalars Q̃ needed

SM loop excluded: the tree level decay would be too large e.g.�tt̄

��⇡ 105.

dark ma'er par/cles, …

Basic ques/ons which cosmology/par/cle physics have to address:

•  What is the cause of the (recent) accelera/on of the expansion of the Universe?

•  What is the exact mechanism for infla/on? Is eternal infla/on a valid op/on?

•  How to explain the ma'er-‐an/ma'er asymmetry?

•  How to compute the energy of the vacuum?

•  How to reconcile gravity with the other forces described by the SM?

•  Why is the Higgs mass stable under radia/ve correc/ons?

•  Why is the Higgs mass so close to the instability fron/er?

This eventually will have to be solved by a single theory: it might be important to address several issues at the same /me

gravita/onal waves

Higgs

Infla/on

accelera/on of the expansion (dark energy)

quantum gravity

new physics@colliders (diphoton…)

stability of the theory

modifica/on of gravity

dark ma'er

Some illustra/ons…

black holes

an/ma'er

gravita/onal waves

Higgs

Infla/on


quantum gravity




dark ma'er

black holes

an/ma'er

Diphoton resonance and dark ma'er

Jan Stark for the ATLAS collaboration Moriond QCD -- March 19-26, 2016 11

Di-photons: search for spin-0 resonancePerform 2D p

0 scan (as function of mass and width

of the hypothetical resonance).

Largest deviation from background-only hypothesis: near 750 GeV width 45 GeV (i.e. 6%)

Local significance: 3.9σGlobal significance: 2.0σ

Report limits on fiducial cross sectionas a function of mass hypothesis,for several width hypotheses.

Example shown here: width of 6%

ATLAS-CONF-2016-xxx

Results presented in the « 750 GeV structure » mini-‐session tend to f avor a spin-‐0 resonance with a rather large width:

Γ/M ≈ 6%

This may be due to the decays of the (pseudo)scalar resonance into (many) dark ma'er par/cles

Dark ma'er portal?

VolksModell (the everybody’s model)

The Sgg and S�� operators can be generated if S couples to charged particles

SQ̄f(yf + i y5f�5)Qf + SAsQ̃⇤sQ̃s

g

g

Q

S

Q

g

g

Extra fermions Q or scalars Q̃ needed

SM loop excluded: the tree level decay would be too large e.g.�tt̄

��⇡ 105.

φ

χ

χ

Extra Q = Dark Matter?

1) The connection with ⌦DM is interesting on its own;2) if �/M ⇠ 0.06 allows to hide many particles that enhance S ! ��;3) if �/M ⇠ 0.06 allows to get tree level S ! DMDM decays.

GDM = 0.01 MS

GDM = 0.03 MS

GDM = 0.06 MS

100 100030 300 300010-2

10-1

1

10

DM mass in GeV

Scalarcouplingy DM

gg

uudd

ss

cc

bb

GDM = 0.01 MS

GDM = 0.03 MS

GDM = 0.06 MS

100 100030 300 300010-2

10-1

1

10

DM mass in GeVPseudo-scalarcouplingyé DM

Direct detection bounds are (weak) irrelevant if S is a scalar (pseudo-scalar).

A. Strumia, QCD

Such a resonance has thus the ideal properties to play a prominent role in the physics ofthe particles that form the dark matter (DM) in the universe [6] and which are the mostwanted particles in both accelerator based experiments and astrophysical experiments.Indeed, the present wisdom summarised by the weakly interacting massive particle orWIMP paradigm, is that an electrically neutral particle with a mass in the few 10 GeV tofew hundred GeV range and interacting weakly with the visible sector, should be stableat cosmological scales and accounts for the DM with a relic abundance that has beenprecisely measured by the WMAP and PLANCK satellites [7, 8].

In this brief note, we investigate the possibility that the observed diphoton resonancemediates the interactions of a spin–1

2 DM particle. We will work in a rather modelindependent framework in which the new particle content associated to both the resonanceand the DM states is not specified and the interactions are described by e↵ective operators.We first show that the measured value of the cosmological relic density can be reproducedfor a wide range of the DM particle masses and couplings. We then discuss the presentbounds and the future sensitivities that can be achieved on the these parameters fromastrophysical detection experiments, both direct such as XENON [9] and LUX [10] andmore precisely in perspective of the new LZ project [11]. We also study indirect searchesat the HESS [12] and FERMI [13] experiments. The complementarity of the approaches isdemonstrated as they are di↵erently sensitive to the CP nature of the mediator resonance.

2. E↵ective interactions of the diphoton resonance

We start by discussing the interactions of the diphoton resonance with the SM and DMparticles. For simplicity, we consider a Majorana DM particle in our work, but thegeneralization to a Dirac fermion is straightforward. The interactions will be described ina model independent way in terms of e↵ective operators for given JP spin–parity quantumnumbers of the � resonance. Two widely di↵erent possibilities need to be considered.

A first one is that the � particle has no direct couplings to SM fermions. In this case,its interactions with gluons and electroweak gauge bosons are given by the following twoLagrangians. In the case of a CP–even 0+ particle, one has [14]:

L0+ =c1⇤�Fµ⌫F

µ⌫ +c2⇤�W µ⌫Wµ⌫ +

c3⇤�Ga

µ⌫Gµ⌫a + g��̄�+m �̄�. (1)

with Fµ⌫ = (@µY⌫�@⌫Yµ) the field strength of the Yµ hypercharge SM gauge field; the sameholds for the SU(2) Wµ fields and the SU(3) Gµ fields. In the case where the mediator ofthe interaction � is a CP–odd or pseudoscalar 0� particle, one would have instead [14]

L0� =c1⇤�Fµ⌫F̃

µ⌫ +c2⇤�W µ⌫W̃µ⌫ +

c3⇤�Ga

µ⌫G̃µ⌫a + ig��̄�

5�+m �̄�. (2)

with F̃µ⌫ = ✏µ⌫⇢�F⇢� and likewise for the SU(2) and SU(3) gauge fields. On should notethat while for LHC physics the CP nature of the � resonance should not matter much, itis very important when it comes to dark matter searches.

The e↵ective couplings of the � state to the SM gauge bosons can be then written as

c�� = c1 cos2 ✓W + c2 sin

2 ✓W , cZZ = c1 sin2 ✓W + c2 cos

2 ✓W , cWW = c2, cgg = c3 (3)

There is also the possibility that the mediator � has direct couplings to SM fermions.As a bilinear term of the form �f̄f is not gauge invariant and explicitly breaks the SM

2

Such a resonance has thus the ideal properties to play a prominent role in the physics ofthe particles that form the dark matter (DM) in the universe [6] and which are the mostwanted particles in both accelerator based experiments and astrophysical experiments.Indeed, the present wisdom summarised by the weakly interacting massive particle orWIMP paradigm, is that an electrically neutral particle with a mass in the few 10 GeV tofew hundred GeV range and interacting weakly with the visible sector, should be stableat cosmological scales and accounts for the DM with a relic abundance that has beenprecisely measured by the WMAP and PLANCK satellites [7, 8].

In this brief note, we investigate the possibility that the observed diphoton resonancemediates the interactions of a spin–1

2 DM particle. We will work in a rather modelindependent framework in which the new particle content associated to both the resonanceand the DM states is not specified and the interactions are described by e↵ective operators.We first show that the measured value of the cosmological relic density can be reproducedfor a wide range of the DM particle masses and couplings. We then discuss the presentbounds and the future sensitivities that can be achieved on the these parameters fromastrophysical detection experiments, both direct such as XENON [9] and LUX [10] andmore precisely in perspective of the new LZ project [11]. We also study indirect searchesat the HESS [12] and FERMI [13] experiments. The complementarity of the approaches isdemonstrated as they are di↵erently sensitive to the CP nature of the mediator resonance.

2. E↵ective interactions of the diphoton resonance

We start by discussing the interactions of the diphoton resonance with the SM and DMparticles. For simplicity, we consider a Majorana DM particle in our work, but thegeneralization to a Dirac fermion is straightforward. The interactions will be described ina model independent way in terms of e↵ective operators for given JP spin–parity quantumnumbers of the � resonance. Two widely di↵erent possibilities need to be considered.

A first one is that the � particle has no direct couplings to SM fermions. In this case,its interactions with gluons and electroweak gauge bosons are given by the following twoLagrangians. In the case of a CP–even 0+ particle, one has [14]:

L0+ =c1⇤�Fµ⌫F

µ⌫ +c2⇤�W µ⌫Wµ⌫ +

c3⇤�Ga

µ⌫Gµ⌫a + g��̄�+m �̄�. (1)

with Fµ⌫ = (@µY⌫�@⌫Yµ) the field strength of the Yµ hypercharge SM gauge field; the sameholds for the SU(2) Wµ fields and the SU(3) Gµ fields. In the case where the mediator ofthe interaction � is a CP–odd or pseudoscalar 0� particle, one would have instead [14]

L0� =c1⇤�Fµ⌫F̃

µ⌫ +c2⇤�W µ⌫W̃µ⌫ +

c3⇤�Ga

µ⌫G̃µ⌫a + ig��̄�

5�+m �̄�. (2)

with F̃µ⌫ = ✏µ⌫⇢�F⇢� and likewise for the SU(2) and SU(3) gauge fields. On should notethat while for LHC physics the CP nature of the � resonance should not matter much, itis very important when it comes to dark matter searches.

The e↵ective couplings of the � state to the SM gauge bosons can be then written as

c�� = c1 cos2 ✓W + c2 sin

2 ✓W , cZZ = c1 sin2 ✓W + c2 cos

2 ✓W , cWW = c2, cgg = c3 (3)

There is also the possibility that the mediator � has direct couplings to SM fermions.As a bilinear term of the form �f̄f is not gauge invariant and explicitly breaks the SM

2

scalar pseudoscalar

Mambrini, Arcadi, Djouadi 1512.04913, Backovic, Mario�, Redigolo 1512.04917; Knappen, Melia, Papucci, Zurek, 1512.04928; …

1512.04933 direct detec/on upper limit

Indirect detec/on: see Morgante et al. 1603.0592

No direct detec/on limit

Region (in blue) where DM has the observed relic aboundance

A note: the dark ma'er-‐black hole connec/on

« Interes/ngly enough, there remains a window for masses 10 M⊙ ︎< MBH < ︎ 100 M⊙ where primordial black holes (PBHs) may cons/tute the dark ma'er. If two PBHs in a galac/c halo pass sufficiently close, they can radiate enough energy in gravita/onal waves to become gravita/onally bound. The bound PBHs will then rapidly spiral inward due to emission of gravita/onal radia/on and ul/mately merge. »

S. Bird, I. Cholis, J. B. Muñoz, Y. Ali-‐Haïmoud, M. Kamionkowski, E. D. Kovetz, A. Raccanelli, A. G. Riess arXiv: 1603.00464 [astro-‐ph.CO]

gravita/onal waves

Higgs

Infla/on


quantum gravity




dark ma'er

black holes

an/ma'er

Higgs infla/on

Higgs h of the original SM cannot be the inflaton

Condi/on to avoid quantum gravity regime during slowroll: quar/c coupling λ≪10-‐2

(whereas λ∼10-‐1)

Need to couple it to space.me curvature R

S = ∫ d4x √-‐g { -‐ (1 + ξ ) R + ∂μh ∂μh -‐ (h2 –v2)2 } h2

MP2

MP2

2 1

2

λ

4

S = ∫ d4x √-‐g { -‐ R -‐ [gμν -‐ (Rμν – R gμν /2 )] ∂μh ∂νh -‐ (h2 –v2)2 } MP

2

2 1

2

λ

4 w2 MP

2

Berzukov, Shaposhnikov 0710.3755 [hep-‐th]…

Germani, Kehagias 1003.2635 [hep-‐ph]…

0

hM4/j2/16

hM4/j2/4

U(r)

0 rend rCOBE r

0h v4/4

0 v

Bezrukov, Shaposhnikov infla/on

Note: problem with unitarity at scale MP/ξ; app. shi� symmetry helps at scale ≫ MP/ξ (infla/on)

Burgess, Lee, Tro' 0902.4465,1002.2730 George, Mooij, Postma, 1310.2157

Bezrukov, Magnin, Shaposhnikov, Sibiryakov 1008.5157 Ferrara, Kallosh, Linde, Marrani, Van Proeyen 1008.2942

Mathema/cal trick: conformal transforma/on on the metric

δT/T ∼ 10-‐5 ⇒ ξ/√λ ∼ 47000

0

hM4/j2/16

hM4/j2/4

U(r)

0 rend rCOBE r

0h v4/4

0 v

Is it dependent on the type of field and on the details of the low energy poten/al?

No!

S = ∫ d4x √-‐g { -‐ (1 + ξ ) R + ∂μh ∂μh -‐ (h2 –v2)2 } h2

MP2

MP2

2 1

2

λ

4

S = ∫ d4x √-‐g { -‐ (1 + ξ f(φ)) R + ∂μh ∂μh -‐ λ f(φ)2 } MP

2

2 1

2

generalize

In the limit ξ large, one obtains the predic/ons of Higgs infla/on

Kallosh, Linde, Roest 1310.3950

Going beyond the Higgs field…

α-‐a'ractors

Kallosh, Linde, Roest 1310.3950

�23

�

�2

�3

�4

0.955 0.960 0.965 0.970 0.975 0.980

-3.0

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

log scale

In fact, one may iden/fy characteris/c classes of models (in a sense very similar to the characteris/c classes of cri/cal phenomena in condensed ma'er physics)

Can one understand this from a broader perspec/ve?

In an infla/on scenario, one first have to solve the classical equa/on of mo/on of the inflaton field in its poten/al.

Suppose that we are in an expanding Universe with cosmic scale factor a(t)

. ≣ d/dt Hubble parameter H(t) ≣ a(t)/a(t)

.

Equa/on of evolu/on of the field φ

φ + 3 H φ = -‐ dV/dφ . . .

φ ρφ = φ2 /2 + V(φ)

V(φ)

pφ = φ2 /2 -‐ V(φ)

.

. energy density

pressure

There is a simple way of extrac/ng an integral of mo/on Bond and Salopek, 1990

Write H(t) = a/a(t) ≣ -‐W(φ)/2 i.e. take the scalar field φ as your clock

Then […] the equa/on of mo/on becomes simply

φ = Wφ

V(φ) = 3W2/4 – Wφ2/2

W(φ) superpoten/al

dφ dφ dt φ 1 dW Wφ

dlna dt dlna H H dφ W = = = = -‐2

.

.

.

.

But

Wφ dW/dφ

φ

evolu/on of φ

dφ Wφ

dlna W = -‐2

evolu/on of φ

dφ Wφ

dlna W = -‐2 ≣ β(φ)

dg

dlnμ = β(g)

renormalisa/on group equa/on in QFT or sta/s/cal physics

field φ gauge coupling g

cosmic scale factor a renormalisa/on scale μ

Where does this come from? Understandable in the context of gauge/gravity duality (AdS/CFT correspondence)

gravity theory in an/ de Si'er

INFLATION

gravity theory in deSi'er

conformally invariant QFT (typically gauge theory w/ β(g)=0)

McFadden, Skenderis

MP2 ↔ -‐MP

2

V↔-‐V

E. Kiritsis 1307.5873

Λ > 0

Λ < 0

Where does this come from? Understandable in the context of gauge/gravity duality

gravity theory in almost

an/ de Si'er

INFLATION

gravity theory in almost deSi'er β(φ) ≠0

conformally invariant QFT (typically gauge theory) + operators β(g)≠0

McFadden Skenderis

MP2 ↔ -‐MP

2

V↔-‐V

E. Kiritsis 1307.5873 McFadden, Skenderis

evolu/on of φ

dφ Wφ

dlna W = -‐2 ≣ β(φ)

dg

dlnμ = β(g)

renormalisa/on group equa/on in QFT or sta/s/cal physics

Note: β(φ) = [ 3(pφ+ρφ)/ρφ]1/2

Vacuum energy: p = -‐ ρ ⇒ β = 0 fixed point

Infla/on: vicinity of a fixed point ns<1, built-‐in instability

ns=1, infla/on for ever

field φ gauge coupling g

cosmic scale factor a renormalisa/on scale μ

Solu/ons classified into universality classes:

Class Ia: β(φ) = βq (φ-‐φ0)q

Class II: β(φ) = -‐β exp[-‐γφ]

V(φ) ∼ A[1-‐ B(φ-‐φ0)q+1+…]

fixed point at ∞

Ex: Higgs infla/on, Starobinsky infla/on

PB, Kiritsis, Mabillard, Pietroni 1407.0820

P.B., Kiritsis, Mabillard, Pietroni 1407.0820

all classes

exponen/al class

Higgs infla/on

Poten/al clues for future theories:

accelera/on of the expansion of the Universe

confirma/on of the basic principles of infla/on

history of the Universe

now

Big Bang

Why is it that vacuum energy seems to dominate at the beginning and at the end of our history?

V

φ

φ has to be very light : mφ ~ H0

~ 10-‐33 eV

φ exchange would provide a long range force similar to gravity: φ has to be extremely weakly coupled to ordinary ma'er unless its mass depends on ρma'er : SCREENING.

ε=(mPV’/V)2 /2«1

mP

Screening: a generic solu/on to a generic problem

Many infla/on models have been recycled into models of dark energy, but the change of scales generates a problem specific to dark energy scalar models.

F. Piazza, Cosmology

Fixed point : zero of β β(φ0)=0

φ0

φ0’ infla/on

infla/on (dark energy?)

gravita/onal waves

Higgs

Infla/on


quantum gravity




dark ma'er

black holes

an/ma'er

Infla/on and the detec/on of gravita/onal waves by ground detectors

In the standard model of infla/on, background of primordial gravita/onal waves is out of reach of LIGO and Virgo.

H02 ΩGW = 10-‐13 (H/10-‐4MPl)2 H0

2 ΩGW = 10-‐13(feq/f) 2(H/10-‐4MPl)2

Fluctua/ons reenter horizon during ma'er era radia/on era

But the situa/on is different if the inflaton scalar field is a pseudoscalar…

Figure 5: Power spectrum of scalar perturbations for all the models with the same parameters and color code of

Fig. 4. The upper horizontal line estimates the PBH bound, the lower one indicates the COBE normalization.

10-15 10-10 10-5 100 10510-29

10-24

10-19

10-14

10-9

0102030405060

f [Hz]

ΩGWh2

N

Figure 6: Gravitational wave spectrum for all the models with the same parameters and color code of Fig. 4.

We are also showing the sensitivity curves for (from left to right): milli-second pulsar timing, eLISA, advanced

LIGO. Current bounds are denoted by solid lines, expected sensitivities of upcoming experiments by dashed

lines. See main text for details.

18

Valerie Domcke, cosmology session, Thursday

Axion-‐type coupling is allowed (and not prevented by SM symmetries): φ Fμν Fμν ~

V. Domcke, M. Pieroni, PB

φ2

Starobinsky

Hilltop

1603.01287

Gauge field has a tachyonic instability: non-‐perturba/ve produc/on during infla/on which induces a new source of tensor modes

Anber, Sorbo; Linde, Mooj, Pajer;…

gravita/onal waves

Higgs

Infla/on


quantum gravity




dark ma'er

black holes

an/ma'er

Dark energy and vacuum energy

The vacuum is the site of quantum field fluctua/ons which contribute to its energy

Vacuum energy problem

Back of an envelope calcula/on :

∼ ρc ∼ 10-‐26 kg/m3

ρ = mP4 ∼ 10120 ρdark energy

par/cle

an/par/cle

Δt ≤ ΔΕ/ħ = 2mc2/ħ

par$cule)

par$cule)

an$par$cule)

an$par$cule) Horizon

singularité)

Fluctua/ons play also an important role close to the horizon of a black hole:

Hawking radia/on

singularity of black hole of mass M

leads in principle to black hole evapora/on

Thermal radia/on T ∝ M-‐1

x

The firewall problem

At the black hole horizon, there appears to be a incompa/bility between the laws of quantum mechanics , the laws of quantum field theory (existence of a unitary S matrix) and the laws of general rela/vity.

AMBS claim that an observer falling into a black hole horizon will encounter a « firewall »

black hole

horizon

Incompa/ble with the equivalence principle: free fall ≣ flat space

1207.3123

Almheiri, Marolf, Polchinski, Sully

This led Hawking and others to reconsider the nature or even the existence of the horizon around black holes…

Who will tell? Probably gravita/onal waves.

The stellar black hole cycles some 105 /mes around the supermassive black hole before plunging into its horizon. Allows to map the geometry of space-‐/me close to the black hole horizon

LISA, 2030

Note the similarities and differences between the cosmological and BH horizon

Black hole Visible Universe

singularity

Observer at infinity

Singularity at infinity

observerXX

Black hole holography Holographic principle ?

t’Hoo�, Susskind See 1208.4645 [gr-‐qc]

US Decadal Survey on Gravitational Physics J. Hartle et al.

neutron star

probed by best accelerators

present Universe

universe at end of infla/on

quantum gravity scale

primordial black hole

Conclusions

We have entered a new world where interconnec/on is probably essen/al.

Un/l now, we have o�en resorted to toy models to make our predic/ons (e.g. infla/on, dark energy, dark ma'er)

If we want to address mul/ple issues, it is important to use theories which are as realis/c and as complete as possible.

Gravita/onal waves will probably become an essen/al tool, not just for astrophysics but for addressing the most fundamental issues of par/cle physics.

dark%maer ,...

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