Physical interpretation of gauge invariant perturbations of spherically symmetric space-times

TL;DR

This paper provides a physical interpretation of gauge-invariant perturbations in spherically symmetric space-times, linking odd parity metric perturbations to gravitational radiation and discussing their use in setting boundary conditions.

Contribution

It introduces a method to interpret gauge-invariant perturbations physically and demonstrates their application in boundary and initial condition setting in perturbation theory.

Findings

Gauge invariants relate to gravitational radiation.

Method for setting boundary conditions using gauge invariants.

Clarification of physical meaning of odd parity perturbations.

Abstract

By calculating the Newman-Penrose Weyl tensor components of a perturbed spherically symmetric space-time with respect to invariantly defined classes of null tetrads, we give a physical interpretation, in terms of gravitational radiation, of odd parity gauge invariant metric perturbations. We point out how these gauge invariants may be used in setting boundary and/or initial conditions in perturbation theory.