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Oleksandr Sobol

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Related publications (9)

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In the framework of mixed Higgs-Starobinsky inflation, we consider the generation of Abelian gauge fields due to their nonminimal coupling to gravity (in two different formulations of gravity-metric and Palatini). We couple the gauge-field invariants F mu ...

2022

Generation of an electromagnetic field nonminimally coupled to gravity during Higgs inflation

Oleksandr Sobol

In the framework of Higgs inflation, we consider the electromagnetic field nonminimally coupled to gravity via the parity-preserving proportional to RF2 and parity-violating proportional to RF (F) over tilde terms. Using the perturbation theory to the lead ...

2021

Schwinger production of scalar particles during and after inflation from the first principles

Oleksandr Sobol

By using the first-principles approach, we derive a system of three quantum kinetic equations governing the production and evolution of charged scalar particles by an electric field in an expanding universe. Analyzing the ultraviolet asymptotic behavior of ...

2020

Gradient expansion formalism for magnetogenesis in the kinetic coupling model

Oleksandr Sobol

In order to describe magnetogenesis during inflation in the kinetic coupling model, we utilize a gradient expansion which is based on the fact that only long-wavelength (superhorizon) modes undergo amplification. For this purpose, we introduce a set of fun ...

2020

Backreaction of electromagnetic fields and the Schwinger effect in pseudoscalar inflation magnetogenesis

Oleksandr Sobol

We study magnetogenesis in axionlike inflation driven by a pseudoscalar field phi coupled axially to the electromagnetic (EM) field (beta/M-p)phi F-mu nu(F) over tilde mu nu with dimensionless coupling constant beta. A set of equations for the inflaton fie ...

2019

Kinetic approach to the Schwinger effect during inflation

Oleksandr Sobol

Using the kinetic approach, we study the impact of the charged particle dynamics due to the Schwinger effect on the electric field evolution during inflation. As a simple model of the electric field generation, we consider the kinetic coupling of the elect ...

2019

Electrical conductivity of hot Abelian plasma with scalar charge carriers

Oleksandr Sobol

We study the electrical conductivity of hot Abelian plasma containing scalar charge carriers in the leading logarithmic order in coupling constant alpha using the Boltzmann kinetic equation. The leading contribution to the collision integral is due to the ...

2019

Influence of backreaction of electric fields and Schwinger effect on inflationary magnetogenesis

Oleksandr Sobol

We study the generation of electromagnetic fields during inflation when the conformal invariance of Maxwell's action is broken by the kinetic coupling f(2)(phi)F mu nu F mu nu of the electromagnetic field to the inflaton field phi We consider the case wher ...

2018

Magnetogenesis In Natural Inflation Model

Oleksandr Sobol

We study the process of inflationary magnetogenesis in the natural single-field inflation model, whose parameters are chosen in accordance with the recent observations by the Planck collaboration [1]. The conformal invariance of the Maxwell action is broke ...

BOGOLYUBOV INST THEORETICAL PHYSICS NATL ACAD SCI UKRAINE2018