Electromagnetic signatures of far-field gravitational radiation in the 1+3 approach

TL;DR

This paper investigates electromagnetic signatures caused by far-field gravitational waves interacting with magnetic fields, deriving analytical solutions and identifying potential detectable effects in astrophysical environments.

Contribution

It introduces a 1+3 relativistic approach to analyze electromagnetic responses to gravitational waves, including nonlinear effects and the inverse Gertsenshtein conversion.

Findings

Electromagnetic radiation significant in highly magnetised pulsars.

Wave-wave resonances are absent with electric-magnetic self-interaction.

Electromagnetic energy flux can be amplified by gravitational wave strength.

Abstract

Gravitational waves from astrophysical sources can interact with background electromagnetic fields, giving rise to distinctive and potentially detectable electromagnetic signatures. In this paper, we study such interactions for far-field gravitational radiation using the 1+3 approach to relativity. Linearised equations for the electromagnetic field on perturbed Minkowski space are derived and solved analytically. The inverse Gertsenshtein conversion of gravitational waves in a static electromagnetic field is rederived, and the resultant electromagnetic radiation is shown to be significant for highly magnetised pulsars in compact binary systems. We also obtain a variety of nonlinear interference effects for interacting gravitational and electromagnetic waves, although wave-wave resonances previously described in the literature are absent when the electric-magnetic self-interaction is taken into account. The fluctuation and amplification of electromagnetic energy flux as the gravitational wave strength increases towards the gravitational-electromagnetic frequency ratio is a possible signature of gravitational radiation from extended astrophysical sources.