On the transverse-traceless gauge condition when matters are presented

TL;DR

This paper explores extending the transverse-traceless gauge condition for gravitational waves to scenarios involving matter, addressing a gap in understanding how matter influences gauge conditions in gravitational wave theory.

Contribution

It proposes possible extensions of the transverse-traceless gauge condition to include matter in Minkowski spacetime, advancing the theoretical framework for gravitational waves in matter-present environments.

Findings

Analysis of gauge conditions in matter-present scenarios

Proposed extensions to the transverse-traceless gauge

Implications for gravitational wave propagation in matter

Abstract

The transverse-traceless gauge condition is an important concept in the theory of gravitational wave. It is well known that vacuum is one of the key conditions to guarantee the existence of the transverse-traceless gauge. Although it is thin, interstellar medium is ubiquitous in the universe. Therefore, it is important to understand the concept of gravitational wave when matter is presented. Bondi-Metzner-Sachs theory has solved the gauge problem related to gravitational wave. But it does not help with the cases when gravitational wave propagates in matters. This paper discusses possible extensions of the transverse-traceless gauge condition to Minkowski perturbation with matter presented.