arXiv subjects

L. A. Panasenko

Publications and source records attributed to L. A. Panasenko.

4 recordsLinked to original sources

arXiv2024

Conversion of high frequency relic gravitational waves into photons in cosmological magnetic field

This work continues the research presented in the article [1], where we estimate the Gertsenshtein effect's influence on the long-wavelength part of relic gravitational wave spectrum. Here, the differential equation system for the Gertsenshtein effect in Friedman-LeMaitre-Robertson-Walker universe, derived in [1], is simplified for gravitational waves in the under-horizon regime during radiation dominance epoch. Then, the obtained system is solved analytically. As a result of the solution analysis a conclusion was made about a significant increase of relic GWs with the frequencies $ k\gtrsim 10^{-11}$ Hz for magnetic field strength about 1 nGs. In addition, at the end of the article model dependency of the result is discussed

gr-qc↗

arXiv2023

Graviton to photon conversion in curved space-time and external magnetic field

The suppression of relic gravitational waves due to their conversion into electromagnetic radiation in a cosmological magnetic field is studied. The coupled system of equations describing gravitational and electromagnetic wave propagation in an arbitrary curved space-time and in external magnetic field is derived. The subsequent elimination of photons from the beam due to their interaction with the primary plasma is taken into account. The resulting system of equations is solved numerically in Friedman-LeMaitre-Robertson-Walker metric for the upper limit of the intergalactic magnetic field strength of 1 nGs. We conclude that the gravitational wave conversion into photons in the intergalactic magnetic field cannot significantly change the amplitude of the relic gravitational wave and their frequency spectrum.

gr-qc↗

arXiv2023

Mixing of scalar and tensor metric perturbations

Metric perturbations in General Relativity are usually separated into three distinct classes: scalar, vector, and tensor. In many cases these modes are separable, i.e. they satisfy independent equations of motion for each mode. However, in the present paper we argue that in many cases tensor and scalar modes are not separable, no matter what gauge conditions are chosen. The propagation of any of these mode depends on the other. A realistic example providing such mixing is presented.

gr-qc↗

arXiv2022

On graviton propagation in curved space-time background

Equation describing propagation of gravitational waves (GW) over arbitrary curved space-time background is analyzed. New terms, which are absent in the conventional homogeneous and isotropic Friedmann cosmology, are found. Some examples of realistic metric, where these new terms manifest themselves, are presented. Possible implications to very low frequency GW are briefly discussed.

gr-qc↗