Abstract:
We extend the conjectured Kerr/CFT correspondence to the case of extremal
Kerr black holes immersed by a 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 nonunitary,
due to the possibility of negative central charge.
