Gravitational wave interactions with a viscous fluid: Core collapse supernova, binary neutron star merger, and accretion around a black hole merger

TL;DR

This paper extends the analysis of gravitational wave interactions with viscous fluids to non-vacuum, spherically symmetric spacetimes, revealing significant damping and heating effects that could impact astrophysical phenomena like supernovae and gamma-ray bursts.

Contribution

It provides new theoretical expressions for GW damping and heating in general static spacetimes and applies these to key astrophysical scenarios, highlighting enhanced effects over previous Minkowski-based models.

Findings

GW damping and heating effects are significantly increased in realistic spacetimes.

Complete damping of GW signals is possible under certain conditions.

Heating can trigger gamma-ray bursts in astrophysical environments.

Abstract

The interaction of gravitational waves (GWs) with matter is normally treated as being insignificant. However, recent work has shown that the interaction with a viscous fluid may be astrophysically important when the distance between the matter and GW source is somewhat smaller than the GW wavelength. Previous work has mainly considered perturbations on a Minkowski background, and here these results are extended to the case that the background is a general, non-vacuum, static, spherically symmetric spacetime. Expressions are obtained for GW damping and the consequent heating of the fluid, and implemented in computer code. The results are applied to astrophysical scenarios: Core collapse supernovae, the post-merger signal from a binary neutron star merger, and matter accreting at a binary black hole merger. It is found that, compared to the Minkowski case, the damping and heating effects increase, in some cases by several orders of magnitude. It is possible for a GW signal to be completely damped, and for the heating to be such that a gamma-ray burst occurs.