On Gauss-Bonnet black hole entropy

TL;DR

This paper explores the calculation of black hole entropy in Gauss-Bonnet and Lovelock gravity using Noether charge methods, addressing issues like negative entropy and ambiguities in the definition.

Contribution

It provides a detailed comparison of entropy calculations across different methods and discusses how to resolve negative entropy issues through additive ambiguities.

Findings

Noether charge approach effectively computes black hole entropy.

Negative entropies can be avoided by choosing appropriate additive constants.

Comparison reveals differences and consistencies among various entropy definitions.

Abstract

We investigate the entropy of black holes in Gauss-Bonnet and Lovelock gravity using the Noether charge approach, in which the entropy is given as the integral of a suitable (n-2) form charge over the event horizon. We compare the results to those obtained in other approaches. We also comment on the appearance of negative entropies in some cases, and show that there is an additive ambiguity in the definition of the entropy which can be appropriately chosen to avoid this problem.