Quasinormal modes of tensor perturbation in Kaluza-Klein black hole for Einstein-Gauss-Bonnet gravity

TL;DR

This paper investigates the quasinormal modes of tensor perturbations in Kaluza-Klein black holes within Einstein-Gauss-Bonnet gravity, revealing how extra dimensions and various parameters influence black hole oscillation frequencies.

Contribution

It extends the analysis of QNMs to Einstein-Gauss-Bonnet gravity for Kaluza-Klein black holes, deriving a scalar perturbation equation and numerically calculating frequencies considering multiple parameters.

Findings

QNMs depend on six parameters including dimension, coupling, and black hole properties.

The compactification dimension has negligible effect on QNM lifetime.

Numerical methods successfully compute the characteristic frequencies.

Abstract

In Einstein-Gauss-Bonnet gravity, we study the quasi-normal modes (QNMs) of the tensor perturbation for the so-called Maeda-Dadhich black hole which locally has a topology $\mathcal{M}^n \simeq M^4 \times \mathcal{K}^{n-4}$. Our discussion is based on the tensor perturbation equation derived in~\cite{Cao:2021sty}, where the Kodama-Ishibashi gauge invariant formalism for Einstein gravity theory has been generalized to the Einstein-Gauss-Bonnet gravity theory. With the help of characteristic tensors for the constant curvature space $\mathcal{K}^{n-4}$, we investigate the effect of extra dimensions and obtain the scalar equation in four dimensional spacetime, which is quite different from the Klein-Gordon equation. Using the asymptotic iteration method and the numerical integration method with the Kumaresan-Tufts frequency extraction method, we numerically calculate the QNM frequencies. In our setups, characteristic frequencies depend on six distinct factors. They are the spacetime dimension $n$, the Gauss-Bonnet coupling constant $\alpha$, the black hole mass parameter $\mu$, the black hole charge parameter $q$, and two ``quantum numbers" $l$, $\gamma$. Without loss of generality, the impact of each parameter on the characteristic frequencies is investigated while fixing other five parameters. Interestingly, the dimension of compactification part has no significant impact on the lifetime of QNMs.