Gravitational wave interactions with magnetized plasmas

TL;DR

This paper investigates how gravitational waves interact with magnetized plasmas, exciting various magnetohydrodynamic modes and leading to potential damping of the waves and plasma wave growth.

Contribution

It provides a comprehensive analysis of GW interactions with magnetized plasmas in arbitrary geometries within the MHD framework, identifying mode excitations and interaction effects.

Findings

All three fundamental MHD modes can be excited by GWs.

Alfven and magnetosonic modes can coherently interact with GWs.

GWs can be damped while plasma waves grow linearly.

Abstract

Gravitational waves (GWs) propagating through a uniformly magnetized plasma interact directly with the magnetic field and excite magnetohydrodynamic (MHD) waves with both electromagnetic and matter components. We study this process for arbitrary geometry in the MHD approximation and find that all three fundamental MHD modes -- slow and fast magnetosonic, and Alfven -- are excited depending on both the polarization of the GW and the orientation of the ambient magnetic field. The latter two modes can interact coherently with the GW resulting in damping of the GW and linear growth of the plasma waves.