Accumulative coupling between magnetized tenuous plasma and gravitational waves

TL;DR

This paper models how gravitational waves induce plasma waves in magnetized plasma, revealing a force-free energy transfer mechanism that could improve detection of high-frequency gravitational waves.

Contribution

It provides explicit solutions for plasma wave generation by gravitational waves in force-free electrodynamics, highlighting a new energy transfer process and potential experimental detection methods.

Findings

Plasma waves co-move with gravitational waves and absorb their energy.

The induced plasma wave's Poynting flux is comparable to vacuum cases.

Current responses may enhance detection sensitivity for high-frequency gravitational waves.

Abstract

We explicitly compute the plasma wave (PW) induced by a plane gravitational wave (GW) travelling through a region of strongly magnetized plasma, governed by force-free electrodynamics. The PW co-moves with the GW and absorbs its energy to grow over time, creating an essentially force-free counterpart to the inverse-Gertsenshtein effect. The time-averaged Poynting flux of the induced PW is comparable to the vacuum case, but the associated current may offer a more sensitive alternative to photodetection when designing experiments for detecting/constraining high frequency gravitational waves. Aside from the exact solutions, we also offer an analysis of the general properties of the GW to PW conversion process, which should find use when evaluating electromagnetic counterparts to astrophysical gravitational waves, that are generated directly by the latter as a second order phenomenon.