Semi-analytic expressions for quasinormal modes of slowly rotating Kerr black holes

TL;DR

This paper derives semi-analytic formulas for the quasinormal mode frequencies of slowly rotating Kerr black holes, improving understanding of their ringdown signals in gravitational wave astronomy.

Contribution

It introduces semi-analytic expressions for Kerr black hole quasinormal modes using alternative equations, extending previous numerical results to quadratic order in rotation.

Findings

Semi-analytic formulas match numerical results closely.

Application of parametrized formalism to different equations.

Enhanced understanding of black hole ringdown signals.

Abstract

We provide semi-analytic expressions for quasinormal mode frequencies of slowly rotating Kerr black holes to the quadratic order in the rotation parameter. We apply the parametrized black hole quasinormal mode ringdown formalism to the Chandrasekhar-Detweiler equation and the Sasaki-Nakamura equation instead of the Teukolsky equation, and compare our result with the previous numerical calculations.