Gravitational Wave Propagation through Viscous Matter

TL;DR

This paper explores how gravitational waves interact with viscous matter in various astrophysical environments, revealing potential significant damping and heating effects that could impact phenomena like gamma-ray bursts.

Contribution

It extends previous models to more realistic backgrounds, showing enhanced GW damping and heating effects in Schwarzschild spacetime and spherical symmetry.

Findings

GW damping and heating are increased in realistic backgrounds.

Significant attenuation of GWs can occur, affecting astrophysical phenomena.

Potential relevance to gamma-ray bursts and other energetic events.

Abstract

It has been known that gravitational waves (GWs) transfer energy to viscous matter through which they propagate, but the effect is too weak to be astrophysically significant. Using linearized perturbations about a Minkowski background, we previously showed that the interaction can become important when the distance between matter and source is smaller than the GW wavelength. Here, we review extensions to more realistic backgrounds, namely Schwarzschild spacetime and a static spherically symmetric setting. We find that GW damping and the associated heating of the viscous fluid are enhanced, and can lead to substantial attenuation or even gamma-ray bursts. We investigate astrophysical scenarios where these effects may be relevant, including core-collapse supernovae, binary neutron star mergers, and accretion onto binary black hole mergers.