Extremal dilatonic black holes in 4D Gauss-Bonnet gravity

TL;DR

This paper investigates extremal dilatonic black holes in 4D Gauss-Bonnet gravity, revealing conditions for global solutions, horizon stretching effects, and entropy modifications due to Gauss-Bonnet corrections.

Contribution

It provides the first detailed analysis of extremal dilatonic black holes in 4D Gauss-Bonnet gravity, including critical dilaton coupling and entropy results.

Findings

Global solutions exist only below a critical dilaton coupling.

Gauss-Bonnet correction stretches the black hole horizon.

Black hole entropy doubles the Bekenstein-Hawking value.

Abstract

This is a report of our recent investigation on the extremal dilatonic black holes in four dimensional Gauss-Bonnet gravity. We found that a global solution can exist only when the dilaton coupling is less than a critical value which can be determined numerically. Moreover, the black hole horizon is stretched by the Gauss-Bonnet correction and the entropy is twice the value given by Bekenstein-Hawking formula.