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)