Counting the microstates of a vacuum black ring

TL;DR

This paper derives the microscopic state count that explains the entropy of extremal vacuum black rings and Kaluza-Klein black holes with ergospheres, linking quantum microstates to classical black hole thermodynamics.

Contribution

It provides a microscopic derivation of the entropy for extremal vacuum black rings and Kaluza-Klein black holes with ergospheres, extending understanding of black hole microstates.

Findings

Microscopic state counting matches Bekenstein-Hawking entropy.

Entropy derived for extremal vacuum black rings.

Entropy also derived for extremal Kaluza-Klein black holes with ergospheres.

Abstract

The Bekenstein-Hawking entropy of an extremal vacuum black ring is derived from a microscopic counting of states. The entropy of extremal Kaluza-Klein black holes with ergospheres is also derived.