Twofold Hidden Conformal Symmetries of the Kerr-Newman Black Hole

TL;DR

This paper proposes that the Kerr-Newman black hole has two distinct holographic dual 2D conformal field theories, each associated with different limits, supported by matching physical quantities and suggesting a microscopic no-hair conjecture.

Contribution

It introduces two separate 2D CFT dual descriptions for the Kerr-Newman black hole based on different limits, expanding the holographic understanding of black hole microstates.

Findings

Matching entropies between gravity and CFTs

Agreement of absorption cross sections

Consistent real-time correlators from both sides

Abstract

In this paper, we suggest that there are two different individual 2D CFTs holographically dual to the Kerr-Newman black hole, coming from the corresponding two possible limits --- the Kerr/CFT and Reissner-Nordstr\"om/CFT correspondences, namely there exist the Kerr-Newman/CFTs dualities. A probe scalar field at low frequencies turns out can exhibit two different 2D conformal symmetries (named by $J$- and $Q$-pictures, respectively) in its equation of motion when the associated parameters are suitably specified. These twofold dualities are supported by the matchings of entropies, absorption cross sections and real time correlators computed from both the gravity and the CFT sides. Our results lead to a fascinating "microscopic no hair conjecture" --- for each macroscopic hair parameter, in additional to the mass of a black hole in the Einstein-Maxwell theory, there should exist an associated holographic CFT$_2$ description.