Parametrized quasinormal modes, greybody factors and their correspondence

TL;DR

This paper investigates how small modifications to general relativity affect quasinormal modes and greybody factors, testing the validity of their correspondence within a parametrized framework.

Contribution

It introduces a detailed parametrized framework for QNMs and GBFs, analyzing their dependence on modification order and testing the QNM-GBF correspondence.

Findings

QNM and GBF dependence on modification order established

Validity regime of QNM-GBF correspondence identified

Framework applicable to small deviations from GR

Abstract

We present a detailed study of quasinormal modes and greybody factors in the context of the parametrized quasinormal mode framework, in which modifications to general relativity are introduced as small corrections in the potential. We deduce the QNMs' and GBFs' dependence on the order of the modifications and their polynomial power. We also test the validity of the recently proposed QNM-GBF correspondence in the pQNM framework by inspecting the regime at which it breaks down.