When is S=A/4?

TL;DR

This paper explores the conditions under which black hole entropy can be assigned and its proportionality to horizon area, highlighting gaps in current understanding and proposing directions for future research.

Contribution

It analyzes the criteria for defining black hole entropy and examines the relationship between entropy and horizon area, emphasizing unresolved conceptual issues.

Findings

Entropy assignment depends on specific horizon conditions

Entropy and area are not always proportional in current models

Identifies gaps in the theoretical understanding of black hole entropy

Abstract

Black hole entropy and its relation to the horizon area are considered. More precisely, the conditions and specifications that are expected to be required for the assignment of entropy, and the consequences that these expectations have when applied to a black hole are explored. In particular, the following questions are addressed: When do we expect to assign an entropy?; when are entropy and area proportional? and, what is the nature of the horizon? It is concluded that our present understanding of black hole entropy is somewhat incomplete, and some of the relevant issues that should be addressed in pursuing these questions are pointed out.