Ringing of rotating black holes in higher-derivative gravity

Abstract

We compute scalar quasinormal mode (QNM) frequencies in rotating black hole solutions of the most general class of higher-derivative gravity theories, to quartic order in the curvature, that reduce to General Relativity for weak fields and are compatible with its symmetries. The wave operator governing the QNMs is not separable, but we show one can extract the QNM frequencies by a projection onto the set of spheroidal harmonics. We have obtained accurate results for the quasinormal frequency corrections relative to Kerr for rotating black holes with dimensionless spins up to ∼ 0.7. We also discuss to what extent our results carry over to the phenomenologically more relevant case of gravitational QNMs. Finally we provide an ancillary computational package that allows one to generalize our calculations to any effective energy-momentum tensor arising from higher-derivative terms in the effective action.

Spectral Problems for Quasinormal Modes of Black Holes

“…In theories beyond general relativity, one often encounters coupled master equations. There are some approaches to analyze such systems [60,[66][67][68][69][70][71][72][73]. It would be interesting to develop the techniques in this article for the coupled master equations.…”

Asymptotic quasinormal modes of string-theoretical d-dimensional black holes

“…From what we mentioned, it is relevant to extend these results to theories beyond Einstein gravity, namely theories with higher derivatives. There are several recent works computing QNMs of black holes with higher derivative corrections coming from different theories, namely [21][22][23][24]. Concerning specifically the asymptotic limit, numerical results have been obtained in [25] for vectorial perturbations of d-dimensional spherically symmetric black holes in Gauss-Bonnet gravity.…”

Gravitational ringing of rotating black holes in higher-derivative gravity

“…In the case of a test scalar field, ref. [52] gave a way of dealing with the non-separability of the wave equation and obtained the QNMs for rotating black holes in a large class of higher-derivative theories were computed. 2 However, when it comes to gravitational perturbations the situation is more precarious, given the difficulty to perform full-fledged perturbation theory for rotating black holes in modified gravity theories.…”