space vacuum and its synthetic model vladimir burdyuzha vladimir burdyuzha astro-space center,...
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Space Vacuum and its Space Vacuum and its Synthetic ModelSynthetic Model
Vladimir Burdyuzha Vladimir Burdyuzha Astro-Space Center, Lebedev Physical Institute, Russian Astro-Space Center, Lebedev Physical Institute, Russian
Academy of Sciences, Moscow Academy of Sciences, Moscow
Miami 2007, 18 December, Fort Lauderdale, Florida Miami 2007, 18 December, Fort Lauderdale, Florida
The refusal of the idea thatThe refusal of the idea that
vacuum is emptiness – the conceptual
statement of modern physics
What is vacuum?What is vacuum?
In classical physics: vacuum is the simplest
system – world without particles and this world is flat (pseudo-euclidean)
In quantum physics: vacuum is a system of
vacuum condensates arising in processes of relativistic phase transitions during early
Universe evolution
In geometrical physics:In geometrical physics:
Vacuum is a state in which geometry of space-time is not deformed
More general: vacuum is a stable state of quantum fields without excitation of wave modes (non – wave components are condensates)
The physical vacuum is a medium The physical vacuum is a medium having specific properties: having specific properties:
It is a carrier of energy and it has pressure;
It has a interior microscopic structure;
It has excited states of wave and soliton types;
It is a medium without resistance;
The wave excitements are usual particles,
soliton excitements are Higgs bosons.
Vacuum has important differences Vacuum has important differences from usual medium:from usual medium:
• It is impossible to connect a definite reference system;
• It has a specific
equation of state ε=-p• It look the same from
any reference system.
This equation of state provides This equation of state provides automatically constancy of energy automatically constancy of energy
density and pressure in all density and pressure in all processes of heating and cooling processes of heating and cooling
The constant density of vacuum energy
was first appeared in Einstein’s equations
as lambda-term:
Rµν – (1/2) R gµν = 8π GN Tµν + Λ gµν
What is vacuum?What is vacuum?
Other words vacuum is a medium with a very complicated structure which had changed during early Universe evolution and which can be rebuilt by change of matter existence
Vacuum in the Universe is the Vacuum in the Universe is the combination of a large number of combination of a large number of mutual connected subsystems:mutual connected subsystems:
• a quark-gluon condensate;
• a Higgs condensate;
• a gravitational condensate and others.
How these subsystems were coordinated?
How compensation of huge positive and
negative contributions did take place?
Probably, Cosmological constant, Probably, Cosmological constant, Vacuum energy, Lambda-term and Vacuum energy, Lambda-term and
Dark energy is the same notionDark energy is the same notion
Besides, dark energy is the reason of accelerated expansion of the Universe after red shift z ~ 0,5 (before this red shift
our Universe had decelerated expansion)
Contents of the UniverseContents of the Universe
• Baryons: 4%• Dark matter: 23%• Dark energy: 73%• Massive neutrino: 0.1%• Spatial curvature: very close to 0 IN GOLDEN ERA OF COSMOLOGY: “We know a lot about our Universe but
understand very little”
Some years agoSome years ago
wehave only three variants of DE: cosmological constant w= -1 quintessence w> -1 phantom energy w< -1
w ≡ p/εp - pressure; ε -density of energy
Today we have:Today we have:
DE models proposed to account for the present cosmic acceleration include:
(i) cosmological constant w=-1 is a special member of this class;
(ii) quintessence models which are inspired by the simplest class of inflation models (a scalar field rolling down);
(iii) the Chaplygin gas (CG) model (p~ - 1/ε);
CG appears to be the simplest CG appears to be the simplest model attempting to unify DE and model attempting to unify DE and
nonbaryonic cold dark matter (DM)nonbaryonic cold dark matter (DM)
(iv) phantom DE; (v) oscillating DE; (vi) models with interactions between DE and DM; (vii) scalar-tensor DE - models; (viii) modified gravity DE - models; (ix) DE driven by quantum effects; (x) higher dimensional “braneworld” models; (xi) holographic dark energy (V.Sahni and A.Starobinsky astro-ph/0610026)
Dark Energy models considered: the ones most commonly used in papers
The equation of state of a “cosmic dark fluid”: Negative w < -1/3 gives an accelerating expansion
Two levels of difficulty:1) A constant EOS w.2) A variable EOS w(z)
)3(3
4
)(
)(DEDE p
ta
ta )
3
1(4
)(
)(w
ta
taDE
wp
Vacuum Condensates:Vacuum Condensates:
A gravitation condensate:
E~ 1019 GeV
•
•
A quark-gluon condensate:
E~ 0.15 GeV
Gravitational Vacuum CondensateGravitational Vacuum Condensate
It produced after first relativistic phase transition P→D4 x [SU(5)] SUSY → or after Universe birth from ”nothing” or from “something”. It represents the collection of topological structures (defects) in curvatures of space-time. Topological structures have the Planck size: D = 3 →WH; D = 2 →micro-membranes; D = 1→micro-strings; D = 0→gas of point defects (monopoles). After Universe inflation these defects were smoothed, stretched and broken up and now they are perceived as structures of Λ-term.
Gravitational Vacuum CondensateGravitational Vacuum Condensate
Topological structures exist in gravitational vacuum and they are consequences of the
parametrizational noninvariance of quantum geometrodynamics (deWitt,1967). The energy density of the system of topological defects contains a constant part corresponding to worm-holes and members of types 1/a3 ;1/a2 ; 1/a corresponding a gas of point defects, micro-membranes, and micro-strings
A new experimental factA new experimental fact
• Dark energy was already boosting the expansion of the Universe as long as nine billions years ago. Investigators using NASA’s Hubble Space Telescope announced this result based on an analysis of the 24 most distant supernovae
during last two years (press-release STSci-2006-52)
A theoretical factA theoretical fact
Probably in the time of the Universe birth the temperature was near 1032 K(1019GeV)
and symmetry was very high. During cooling the Universe was losing symmetry
by phase transitions. Nobody knows an exact chain of these transitions. The low energy part of this chain must be the next:
→ D4 x SU(3) x U(1) → D4 x U(1) 100 GeV 150 MeV
It was a quantum chromodynamical It was a quantum chromodynamical phase transition phase transition
• Chiral QCD symmetry SU(3)L x SU(3)R is
not exact and pseudogoldstone bosons are physical realization of this symmetry breaking. It leads to appearance an octet of pseudoscalar Goldstone states in spectrum of particles. π- mesons, as the lightest particles of this octet, carry the main contribution in periodic collective motion of a nonperturbative vacuum condensate In this process π-mesons are excitations of the ground state (QCD vacuum).D.A.Kirzhnits(2000)
Zeldovich’s approximationZeldovich’s approximation
• Λ = 8 π G2 mπ6 h-4
• ΩΛ = ρΛ /ρcr ≡ Λ c2 / 3H02
If H0 = 72.5 (km/sec)/Mpc then ΩΛ ~ 0.7
Therefore very probably that in the present
epoch vacuum energy is a vacuum condensate of last relativistic phase trans.
Space vacuum is a complex Space vacuum is a complex systems of condensates of systems of condensates of quantum fields which were quantum fields which were
produced in the result produced in the result of relativistic phase transitions during
cooling of the Universe. We researched a quark-gluon phase transition after which vacuum energy has hardened and it has become cosmological constant.
Before this Before this
a vacuum component of the Universe was
changing by jumps during phase transitions
since vacuum condensates of quantum
fields carried a negative contribution in vacuum
positive energy density. This quintessence
period of the Universe evolution took place
during first parts of a second when our Universe was losing the high symmetry.
ΛΛ-term (Vacuum Energy)-term (Vacuum Energy)
Probably Λ-term must consist of some components:
Λ = ΛQF + ΛWH + ΛG
ΛΛ-term consists of some -term consists of some componentscomponents
ΛSM = - (m2H m2
w) /2g2 -
- (1/128π2)(m4H + 3m4
z + 6m4w - 12 m4
t)
λ G is formed by a gravitational vacuum condensate
λG = (9π2/2 ǽ2 )λn
Final resultsFinal results
1. 1019 GeV → 150 MeV - quintessence period of vacuum evolution t«1 sec 2. 150 MeV → 10-4 eV – vacuum energy is practically constant t » 1 sec
3. gravitational vacuum condensate has also fixed time in our Universe (if we live in multiverse) 4. 3-dimensional topological defects renormalize Λ-
term (Astrophys. Space Sci. 305, 235, 2006)