Universal area spectrum in single-horizon black holes

Abstract

We investigate highly damped quasinormal mode of single-horizon black holes motivated by its relation to the loop quantum gravity. Using the WKB approximation, we show that the real part of the frequency approaches the value TH ln 3 for dilatonic black hole as conjectured by Medved et al. and Padmanabhan. It is surprising since the area specrtum of the black hole determined by the Bohr's correspondence principle completely agrees with that of Schwarzschild black hole for any values of the electromagnetic charge or the dilaton coupling. We discuss its generality for single-horizon black holes and the meaning in the loop quantum gravity.

Quasinormal modes for single horizon black holes in generic 2D dilaton gravity

“…Then, since the final result for the mode spectra depends only on κ and a, it is feasible that, for any such black hole, the real part of the frequencies may asymptote to T ln (3). If this were indeed the case, it would establish conjectures of universality that have been made in, for instance, [17,41]. This type of universality should be regarded as a minimal requirement if one is to take the Hod conjecture [5] seriously as a statement about quantum gravity.…”

“…Note that this form can also be used as the basis for a WKB analysis of the quasinormal modes[12,41]. The full WKB analysis for the case of generic two-dimensional dilatonic gravity will be presented elsewhere 14.…”