Universal entropy relations: entropy formulae and entropy bound

TL;DR

This paper reviews universal entropy relations in multi-horizon black holes, highlighting their role in understanding black hole entropy, entropy bounds, and their application across various gravity theories.

Contribution

It introduces entropy relations as a versatile technique for analyzing entropy bounds and explores their implications in different gravity models.

Findings

Entropy relations improve understanding of black hole entropy.

They provide a method for handling entropy bounds and sums.

Applications extend to various gravity theories like massive gravity and Horava-Lifshitz gravity.

Abstract

We survey the applications of universal entropy relations in black holes with multi-horizons. In sharp distinction to conventional entropy product, the entropy relationship here not only improve our understanding of black hole entropy but was introduced as an elegant technique trick for handling various entropy bounds and sum. Despite the primarily technique role, entropy relations have provided considerable insight into several different types of gravity, including massive gravity, Einstein-Dilaton gravity and Horava-Lifshitz gravity. We present and discuss the results for each one.