Entropy/Area spectra of the charged black hole from quasinormal modes

TL;DR

This paper investigates the quantized area spectrum of a stringy charged Garfinkle-Horowitz-Strominger black hole using quasinormal modes, finding it to be equally spaced and charge-independent, extending previous results to string-inspired black holes.

Contribution

It extends the analysis of black hole area spectra to stringy charged black holes, showing the spectrum is equally spaced and unaffected by charge, using quasinormal mode methods.

Findings

Area spectrum is equally spaced with spacing 8πħ.

Spectrum is independent of the black hole's charge q.

Results align with previous methods for non-extremal black holes.

Abstract

With the new physical interpretation of quasinormal modes proposed by Maggiore, the quantum area spectra of black holes have been investigated recently. Adopting the modified Hod's treatment, results show that the area spectra for black holes are equally spaced and the spacings are in a unified form, $\triangle A=8\pi \hbar$, in Einstein gravity. On the other hand, following Kunstatter's method, the studies show that the area spectrum for a nonrotating black hole with no charge is equidistant. And for a rotating (or charged) black hole, it is also equidistant and independent of the angular momentum $J$ (or charge $q$) when the black hole is far from the extremal case. In this paper, we mainly deal with the area spectrum of the stringy charged Garfinkle-Horowitz-Strominger black hole, originating from effective action that emerges in the low-energy string theory. We find that both methods give the same results-that the area spectrum is equally spaced and does not depend on the charge $q$. Our study may provide new insights into understanding the area spectrum and entropy spectrum for stringy black holes.