Magnetized Kerr/CFT Correspondence

TL;DR

This paper extends the Kerr/CFT correspondence to extremal Kerr black holes in magnetic fields, computing the central charge and matching the black hole entropy with a dual 2D CFT, suggesting a non-unitary dual theory.

Contribution

It generalizes the Kerr/CFT correspondence to magnetized extremal Kerr black holes and computes the associated central charge and entropy.

Findings

Central charge computed for extremal Melvin-Kerr black holes.

Macroscopic entropy matches microscopic CFT calculation.

Dual CFT may be non-unitary due to negative central charge.

Abstract

We extend the conjectured Kerr/CFT correspondence to the case of extremal Kerr black holes immersed by an magnetic field, namely the extremal Melvin-Kerr black holes. We compute the central charge which appears in the associated Virasoro algebra generated by a class of diffeomorphisms that satisfies a set of boundary conditions in the near horizon of an extremal Melvin-Kerr black hole. Our results support the Kerr/CFT conjecture, where the macroscopic Bekenstein-Hawking entropy for an extremal Melvin-Kerr black hole matches the result obtained from a dual 2D CFT microscopic computation using Cardy formula. Interestingly, the dual CFT description could be non-unitary, due to the possibility of negative central charge.