Plasma waves driven by gravitational waves in an expanding universe

TL;DR

This paper investigates how gravitational waves can excite plasma waves in an expanding universe, showing that magnetosonic waves are generated without disrupting the universe's large-scale uniformity.

Contribution

It demonstrates the excitation of large amplitude magnetosonic waves by gravitational waves in a homogeneous, isotropic FRW universe with a weak magnetic field.

Findings

Magnetosonic waves are excited by gravitational waves in an FRW universe.

The magnetic field remains weak and does not break homogeneity or isotropy.

Large amplitude plasma waves can be generated without disrupting cosmic uniformity.

Abstract

In a Friedmann-Robertson-Walker (FRW) cosmological model with zero spatial curvature, we consider the interaction of the gravitational waves with the plasma in the presence of a weak magnetic field. Using the relativistic hydromagnetic equations it is verified that large amplitude magnetosonic waves are excited, assuming that both, the gravitational field and the weak magnetic field do not break the homogeneity and isotropy of the considered FRW spacetime.