arXiv subjects

V. N. Pervushin

Publications and source records attributed to V. N. Pervushin.

65 records · Page 4Linked to original sources

arXiv1997

Cosmological Vacuum in Unified Theories

The unification of the Einstein theory of gravity with a conformal invariant version of the standard model for electroweak interaction without the Higgs potential is considered. In this theory, a module of the Higgs field is absorbed by the scale factor component of metric so that the evolution of the Universe and the elementary particle masses have one and the same cosmological origin and the flat space limit corresponds to the $σ$-model version of the standard model. The red shift formula and Hubble law are obtained under the assumption of homogeneous matter distribution. We show that the considered theory leads to a very small vacuum density of the Higgs field $ρ_ϕ^{Cosmic}=10^{-34}ρ_{cr}$ in contrast with the theory with the Higgs potential $ρ_ϕ^{Higgs}=10^{54}ρ_{cr}$.

gr-qc↗

arXiv1997

Dirac and Friedmann Observables in Quantum Universe with Radiation

Relations between the Friedmann observables of the expanding Universe and the Dirac observables in the generalized Hamiltonian approach are established for the Friedmann cosmological model of the Universe with the field excitations imitating radiation. A full separation of the physical sector from the gauge one is fulfilled by the method of the gaugeless reduction in which the gravitational part of the energy constraint is considered as a new momentum. We show that this reduction removes an infinite factor from the Hartle -- Hawking functional integral, provides the normalizability of the Wheeler -- DeWitt wave function, clarifies its relation to the observational cosmology, and picks out a conformal frame of Narlikar.

gr-qc↗

arXiv1997

Description of Friedmann Observables in Quantum Universe

The solution of the problem of describing the Friedmann observables (the Hubble law, the red shift, etc.) in quantum cosmology is proposed on the basis of the method of gaugeless Hamiltonian reduction in which the gravitational part of the energy constraint is considered as a new momentum. We show that the conjugate variable corresponding to the new momentum plays a role of the invariant time parameter of evolution of dynamical variables in the sector of the Dirac observables of the general Hamiltonian approach. Relations between these Dirac observables and the Friedmann observables of the expanding Universe are established for the standard Friedmann cosmological model with dust and radiation. The presented reduction removes an infinite factor from the functional integral, provides the normalizability of the wave function of the Universe and distinguishes the conformal frame of reference where the Hubble law is caused by the alteration of the conformal dust mass.

gr-qc↗

arXiv1997

On the Cosmological Origin of the Homogeneous Scalar Field in Unified Theories

We consider the possibility of describing the Higgs effect in unified theories without the Higgs potential in the presence of the Einstein gravity with the conformal gravity-scalar coupling under the assumption of homogeneous matter distribution. The scalar field values can be found from the Friedmann equations for the homogeneous Universe. The considered cosmological mechanism solves the vacuum density problem (we got $ρ_ϕ^{Cosmic}=10^{-34}ρ_{cr}$ instead of $ρ_ϕ^{Higgs}=10^{54}ρ_{cr}$),and exludes the monopole creation and the domain walls.

gr-qc↗

arXiv1996

Squeezed condensate of gluons and $η-η'$ mass difference

We consider a mechanism to create the $η- η'$ mass difference by the gluon anomaly in a squeezed vacuum. We find that the mass shift of the $η_0$ governing this mass difference is determined by the magnetic part of the gluon condensate. For the squeezed vacuum this magnetic part coincides with the total gluon condensate, so that we get a relation between the gluon condensate and the mass shift of the $η_0$ as a function of the strong coupling constant $α_s$. The values of the gluon condensate obtained through this relation are compared with the value by Shifman, Vainshtein and Zakharov and the recent update values by Narison.

nucl-th↗

arXiv1995

Coherent and squeezed condensates in massless $λφ^4$ theory

Generalizing the Bogoliubov model of a weakly non-ideal Bose gas to massless $λφ^4$ theory we show that spontaneous breaking of symmetry occurs due to condensation in a coherent vacuum % which is energetically favoured compared to the perturbative one. and leads to a vacuum energy density which is lower than that obtained by Coleman and Weinberg using the one-loop effective potential method. We discuss the alternative of a squeezed condensate and find that for the massless $λφ^4$ theory spontaneous symmetry breaking to a squeezed vacuum does not occur.

hep-th↗

arXiv1995

Bogoliubov condensation of gluons and spontaneous gauge symmetry breaking in QCD

The problem of the gluonic quasiparticle excitations in QCD is considered under the aspect of the condensation of gluon pairs in the ''squeezed'' vacuum. The present approach is a field theoretical generalization of the Bogoliubov model which successfully reproduced the Landau spectrum in the microscopic theory of superfluidity. We construct a gauge invariant QCD Hamiltonian by formally solving the Gauss equation such that the physical variables are separated by a non-Abelian projection operator, instead of fixing a gauge. By using Dirac quantization we show that the Bogoliubov condensation of gluon pairs destroys this projection operator, and the spontaneous appearance of a gluon mass is accompanied by a longitudinal component for the gluon field in correspondence with the relativistic covariance. Gauge symmetry is broken spontaneously since the gauge invariance of the Hamiltonian is not shared by the vacuum. The squeezed vacuum in the present model is characterized by one free parameter related to the contraction of a pair of zero momentum gluon fields which is fixed from the difference of the $η'$ and the $η$ - meson masses ($ U(1)$-problem) and results in a value for the gluon condensate which is in good agreement with the value obtained by Shifman, Vainshtein and Zakharov.

hep-ph↗

arXiv1995

The Time Surface Term in Quantum Gravity

The role of the time surface term in the ADM Hamiltonian formulation of general relativity is investigated. We show that the variable contained in the time surface term (the scale factor) plays the role of a time-like variable. The conjugated variable represents the energy density in the reduced phase space, where the Schrödinger like equation for a wave function is derived. The contribution from the surface term to the phase of the wave function allows us to define {\bf the phase time of the quantum Universe} so that it coincides with {\bf the proper time as an invariant interval} for the classical dust filled Universe. The quantum scenario of the evolution of the Universe filled in by the Weinberg-Salam fields is considered. The wave function of the early Universe as the functional from the Higgs fields and scale factor realizes the unitary irreducible representation of the SO(4,1) group. The elementary particle masses are determined by the angles of the scale--scalar field mixing.

hep-ph↗

arXiv1995

Covariant Gauges for Constrained Systems

The method of constructing of extended phase space for singular theories which permits the consideration of covariant gauges without the introducing of a ghost fields, is proposed. The extension of the phase space is carried out by the identification of the initial theory with an equivalent theory with higher derivatives and applying to it the Ostrogradsky method of Hamiltonian description .

hep-th↗

arXiv1995

On Abelianization of First Class Constraints

The systematic method for the conversion of first class constraints to the equivalent set of Abelian one based on the Dirac equivalence transformation is developed. The representation for the corresponding matrix performing this transformation is proposed. This representation allows one to lead the problem of abelianization to the solution of a certain system of first order {\it linear } differential equations for matrix elements .

hep-th↗

arXiv1995

On Admissible Gauges for Constrained Systems

The {\it {gauge - fixing} } and {\it gaugeless } methods for reducing the phase space in the generalized Hamiltonian dynamics are compared with the aim to define the class of admissible gauges . In the gaugeless approach, the reduced phase space of a Hamiltonian system with the first class constraints is constructed locally, without any gauge fixing, using the following procedure: abelianization of constraints with the subsequent canonical transformation so that some of the new momenta are equal to the new abelian constraints. As a result the corresponding conjugate coordinates are ignorable ( nonphysical ) one while the remaining canonical pairs corresponds to the true dynamical variables. This representation for the phase space prompts us the definition of subclass of admissible gauges -- canonical gauges as functions depending only on the ignorable coordinates. A practical method to recognize the canonical gauge is proposed .

hep-th↗