Energy-momentum response to metric perturbations in the fluid dynamic regime

TL;DR

This paper investigates how small metric perturbations affect the energy-momentum tensor in relativistic fluids, with implications for gravitational wave phenomena and damping mechanisms.

Contribution

It combines gravitational Ward identities with Mueller-Israel-Stewart fluid equations to explicitly compute the linear response of the energy-momentum tensor to metric perturbations.

Findings

Explicit response functions for energy-momentum tensor to metric perturbations.

Insights into gravitational wave production in relativistic fluids.

Analysis of gravitational wave damping in fluid environments.

Abstract

The interplay of relativistic fluid dynamics and spacetime geometry is discussed in the regime of small wave numbers and frequencies. A combination of gravitational Ward identities and fluid dynamic equations of motion in the Mueller-Israel-Stewart formulation is used to explicitly determine the retarded linear response of the energy-momentum tensor to metric perturbations. We also discuss applications to gravitational wave production and the damping of gravitational waves in a relativistic fluid.