Gravito-electromagnetic resonances in Minkowski space

TL;DR

This paper investigates how gravitational waves can induce and amplify electromagnetic waves in Minkowski space, revealing resonant effects and potential astrophysical implications.

Contribution

It demonstrates the possibility of resonant amplification of electromagnetic waves driven by gravitational waves, including linear growth over time, in a Minkowski background.

Findings

Resonant amplification can lead to linear growth in electromagnetic wave amplitude.

Electromagnetic beat-like signals result from Weyl-Maxwell interactions.

Order-of-magnitude estimates suggest astrophysical relevance of the effects.

Abstract

We consider the interaction between gravitational and electromagnetic radiation propagating on a Minkowski background and look into the effects of the former upon the latter. Not surprisingly, the coupling between these two sources leads to gravitationally driven electromagnetic waves. At the second perturbative level, the driving force appears as the superposition of two waves, the properties of which are decided by the initial conditions. We find that the Weyl-Maxwell interaction typically leads to electromagnetic beat-like signals and, in some cases, to the resonant amplification of the driven electromagnetic wave. For physically reasonable initial conditions, we show that these resonances imply a linear (in time) growth for the amplitude of the electromagnetic signal, with the overall amplification also depending on the strength of the driving gravity wave. Finally, we provide order-of-magnitude estimates of the achieved amplification by applying our analysis to astrophysical environments where both gravitational and electromagnetic waves are expected to coexist.