Hawking evaporation of Einstein-Gauss-Bonnet AdS black holes in $D\geqslant 4$ dimensions

TL;DR

This paper studies the evaporation process of Einstein-Gauss-Bonnet AdS black holes across various dimensions, revealing how the black hole lifetime and end states depend on the coupling constant and spacetime dimension.

Contribution

It provides a detailed analysis of black hole evaporation in Einstein-Gauss-Bonnet gravity, highlighting dimension-dependent behaviors and the impact of the coupling constant on black hole remnants and singularities.

Findings

Black hole lifetime is dimension-dependent, finite in D≥6 for α>0.

In D=4,5 with α>0, black holes become remnants with infinite lifetime.

For α<0, black holes evaporate to a minimal mass with an additional singularity.

Abstract

Einstein-Gauss-Bonnet theory is a string-generated gravity theory when approaching the low energy limit. By introducing the higher order curvature terms, this theory is supposed to help to solve the black hole singularity problem. In this work, we investigate the evaporation of the static spherically symmetric neutral AdS black holes in Einstein-Gauss-Bonnet gravity in various spacetime dimensions with both positive and negative couping constant $\alpha$. By summarizing the asymptotic behavior of the evaporation process, we find the lifetime of the black holes is dimensional dependent. For $\alpha>0$, in $D\geqslant6$ cases, the black holes will be completely evaporated in a finite time, which resembles the Schwarzschild-AdS case in Einstein gravity. While in $D=4,5$ cases, the black hole lifetime is always infinite, which means the black hole becomes a remnant in the late time. Remarkably, the cases of $\alpha>0, D=4,5$ will solve the terminal temperature divergent problem of the Schwarzschild-AdS case. For $\alpha<0$, in all dimensions, the black hole will always spend a finite time to a minimal mass corresponding to the smallest horizon radius $r_{min}=\sqrt{2|\alpha|}$ which coincide with an additional singularity. This implies that there may exist constraint conditions to the choice of coupling constant.