Black hole entropy in modified gravity models

TL;DR

This paper investigates black hole entropy in modified gravity models using the Noether charge method, revealing corrections to classical entropy and proposing entropy positivity as a viability criterion for these theories.

Contribution

It provides a detailed analysis of black hole entropy corrections in modified gravity and introduces entropy positivity as a new constraint on model viability.

Findings

Corrections to Einsteinian black hole entropy are identified.

Entropy positivity constrains the viability of modified gravity models.

Explicit calculations for Schwarzschild and Schwarzschild-de Sitter black holes.

Abstract

An analysis of some modified gravity models, based on the study of pure Schwarzschild and of Schwarzschild-de Sitter black holes, and involving the use of the Noether charge method, is carried out. Corrections to the classical Einsteinian black hole entropy appear. It is shown explicitly how the condition of positive entropy can be used in order to constrain the viability of modified gravity theories.