Understanding the area proposal for extremal black hole entropy

TL;DR

This paper explores how extremal black hole entropy can be derived from an approach that sums over topologies and applies the extremality condition post-quantization, extending the area law beyond non-extremal cases.

Contribution

It introduces a method to derive extremal black hole entropy by summing over topologies and imposing extremality after quantization, providing a new perspective on the area law.

Findings

Area law can be derived for extremal black holes in certain models.

Summing over topologies and post-quantization extremality reproduces the area law.

Supports the idea that extremal black hole entropy can be understood similarly to non-extremal cases.

Abstract

Whereas the usual understanding is that the entropy of only a non-extremal black hole is given by the area of the horizon, there are derivations of an area law for extremal black holes in some model calculations. It is explained here how such results can arise in an approach where one sums over topologies and imposes the extremality condition after quantization.