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A. Yu. Petrov

Publications and source records attributed to A. Yu. Petrov.

At least 91 records · Page 5Linked to original sources
arXiv2021

Vortex solutions in nonpolynomial scalar QED

In order to investigate possible topological vortex structures in generalized models, we developed a perturbative generation approach for scalar-vector theories. We demonstrate explicitly that the dielectric permeability functions must have a nonpolynomial shape, i. e., the form of the logarithmic function. Basing on this result, we built models in $(2+1)D$ with logarithmic dielectric permeability in order to investigate the presence of topological vortex structures in a Maxwell model. This type of scalar-vector models is important because they can generate stationary field solutions in theories describing the dynamics of the scalar field. As examples, we chose models of the complex scalar field coupled to the Maxwell field. Subsequently, we investigated the model's Bogomol'nyi equations to describe the field configurations. Then, we demonstrate numerically, for an ansatz with rotational symmetry, that the solutions of the complex scalar field generating minimum energy configurations are topological structures depending on the parameters obtained in the perturbative generation of the vector-scalar theory.

hep-th↗
arXiv2020

Strong gravitational lensing in a spacetime with topological charge within the Eddington-inspired Born-Infeld gravity

In this work we calculate the angular deflection of light in the strong field limit in two spacetimes which were previously studied within the Eddington-inspired Born-Infeld gravity (EiBI), namely, a black hole and a wormhole, both with topological charge. We show that the presence of the parameters characterizing EiBI and the topological charge promote significant changes in the angular deflection of light with respect to that one obtained in Schwarzschild spacetime. Using the expression for angular deflection in the strong field limit, we calculate the position and magnification of the respective relativistic images.

gr-qc↗
arXiv2020

Non-Abelian extension of the aether term and the Gribov problem

In this paper, we treat the proper path integral quantization of the Yang-Mills-aether (YM-aether) system by dealing with the extra gauge copies in the Landau gauge. Within Gribov's prescription to get rid of such remaining gauge copies, we explicitly derive the Gribov parameter dependence of the coupling constant and of the Lorentz violation aether term. The ultraviolet limit is investigated under the light of recent bounds on the magnitude of the non-Abelian aether parameter, and we show that the Gribov parameter can be disregarded in that limit.

hep-th↗
arXiv2020

Gödel-type Solutions in Cubic Galileon Gravity

We address the homogeneous in space and time (ST-homogeneous) Gödel-type metrics within the cubic galileon theory, a particular class of generalized galileon theories. We check the consistency of such spacetimes for a physically well-motivated matter content, namely, a perfect fluid and an electromagnetic field. In this scenario, we find that the admissible solutions impose constraints on the constant couplings ($c_{i}$'s) of the cubic galileon theory to ensure the consistency. Also, we show the existence of a vacuum completely causal solution.

gr-qc↗
arXiv2020

No radiative corrections to the Carroll-Field-Jackiw term beyond one-loop order

We demonstrate explicitly the absence of the quantum corrections to the Carroll-Field-Jackiw (CFJ) term beyond one-loop within the Lorentz-breaking CPT-odd extension of QED. The proof holds within two prescriptions of quantum calculations, with the axial vector in the fermion sector {}treated either as a perturbation or as a contribution in the exact propagator of the fermion field.

hep-th↗
arXiv2020

Introduction to modified gravity

This paper is a collection of lecture notes on modified gravity. Various modified gravity models formulated within the Riemannian formalism are discussed.

gr-qc↗
arXiv2020

Gravitational lensing in a black-bounce traversable wormhole spacetime

In this work, we calculate the deflection angle of light in a spacetime that interpolates between regular black holes and traversable wormholes, depending on the free parameter of the metric. Afterwards, this angular deflection is substituted into the lens equations which allows to obtain physically measurable results, such as the position of the relativistic images and the magnifications.

gr-qc↗
arXiv2020

1/N Expansion for Horava-Lifshitz like four-fermion models

We study a class of four-fermion Gross-Neveu like models in four dimensions with critical exponents $z=2$ and $z=3$. The models with $z=2$ are known to be perturbatively nonrenormalizable but are shown to be renormalizable in the context of the $1/N$ expansion. We calculate explicitly the effective potential for these models.

hep-th↗
arXiv2019

Horava-Lifshitz four-fermion model revisited and dynamical symmetry breaking

In this paper, we develop studies of the dynamical symmetry breaking in the Horava-Lifshitz four-fermion model for the specific case $z=3$ and explicitly demonstrate that for various space-time dimensions, one could arrive at the theory displaying both dynamical generation of the Lorentz symmetry for the kinetic term and arising the positively defined potential at the same time. At the same time, for $D=3$, the Lorentz invariant Chern-Simons term is generated.

hep-th↗
arXiv2019

Lorentz symmetry breaking in a Yang-Mills theory within the Gribov restriction

In this paper we take into account the existence of Gribov copies in a four-dimensional Yang-Mills theory in the Landau gauge with an effective Lorentz symmetry breaking, induced by the Carroll-Field-Jackiw (CFJ) term. The self consistent gap equation of the Gribov parameter is properly derived and, provided observational bounds to the amplitude of the CFJ parameter in the $SU(2)$ gauge theory, a qualitative analysis of the Gribov parameter and of the poles of the propagator is developed.

hep-th↗
arXiv2019

Nonlinear $σ$-models in the Eddington-inspired Born-Infeld Gravity

In this paper we consider two different nonlinear $σ$-models minimally coupled to Eddington-inspired Born-Infeld gravity. We show that the resultant geometries represent minimal modifications with respect to those found in GR, though with important physical consequences. In particular, wormhole structures always arise, though this does not guarantee by itself the geodesic completeness of those space-times. In one of the models, quadratic in the canonical kinetic term, we identify a subset of solutions which are regular everywhere and are geodesically complete. We discuss characteristic features of these solutions and their dependence on the relationship between mass and global charge.

hep-th↗
arXiv2019

Podolsky electrodynamics from a condensation of topological defects

In this paper we demonstrate the arising of higher-derivative contributions to the effective action of electrodynamics on the base of generalized Julia-Toulouse mechanism and explicitly show that the complete effective action generated within this methodology is nonlocal.

hep-th↗
arXiv2019

Dynamical Lorentz symmetry breaking in a tensor bumblebee model

In this paper, we formulate a theory of the second-rank antisymmetric (pseudo)tensor field minimally coupled to a spinor, calculate the one-loop effective potential of the (pseudo)tensor field, and, explicitly, demonstrate that it is positively defined and possesses a continuous set of minima, both for tensor and pseudotensor cases. Therefore, our model turns out to display the dynamical Lorentz symmetry breaking. We also argue that, contrarily to the derivative coupling we use here, derivative-free couplings of the antisymmetric tensor field to a spinor do not generate the positively defined potential and thus do not allow for the dynamical Lorentz symmetry breaking.

hep-th↗