Universal Entropy and Hawking Radiation of Near-Extremal AdS$_4$ Black Holes

TL;DR

This paper calculates the entropy of near-extremal AdS4 black holes using three methods, confirming a universal formula and providing insights into Hawking radiation through microscopic analysis.

Contribution

It extends the Kerr/CFT correspondence to near-extremal black holes and demonstrates the universality of entropy calculations across different approaches.

Findings

Exact agreement of entropy from gravity, Kerr/CFT, and CFT methods

Extension of Kerr/CFT to near-extremal cases with new central charges

Microscopic foundation for Hawking radiation in AdS4 black holes

Abstract

We compute the Bekenstein-Hawking entropy of near-extremal asymptotically AdS$_4$ electrically charged rotating black holes using three different methods: (i) from the gravity solution, (ii) from the near-horizon Kerr/CFT correspondence and (iii) from the boundary conformal field theory. The results from these three different approaches match exactly, giving us a unique and universal expression for the entropy and the microstate counting of near-extremal AdS black holes via the AdS/CFT correspondence. In the second method, we extend the Kerr/CFT correspondence to the near-extremal case to compute the left and right central charges. We also use hidden conformal symmetry of the near-horizon geometry to compute the Frolov-Thorne temperatures. From the results of the near-extremal AdS$_4$ black hole entropy, we provide a microscopic foundation for Hawking radiation.