Entropy of near-extremal black holes in AdS_5

TL;DR

This paper constructs microstates of near-extremal AdS_5 black holes via defects in dual Yang-Mills theory, revealing new dualities and geometries that account for black hole entropy.

Contribution

It introduces a novel description of black hole microstates using defects in BPS operators and explores new decoupling limits and dualities in the gauge/gravity correspondence.

Findings

Defects dominate black hole entropy calculations.

New decoupling limits relate field theory to near-horizon geometries.

Evidence of an infrared duality exchanging gauge group rank and R-charge.

Abstract

We construct the microstates of near-extremal black holes in AdS_5 x S^5 as gases of defects distributed in heavy BPS operators in the dual SU(N) Yang-Mills theory. These defects describe open strings on spherical D3-branes in the S^5, and we show that they dominate the entropy by directly enumerating them and comparing the results with a partition sum calculation. We display new decoupling limits in which the field theory of the lightest open strings on the D-branes becomes dual to a near-horizon region of the black hole geometry. In the single-charge black hole we find evidence for an infrared duality between SU(N) Yang-Mills theories that exchanges the rank of the gauge group with an R-charge. In the two-charge case (where pairs of branes intersect on a line), the decoupled geometry includes an AdS_3 factor with a two-dimensional CFT dual. The degeneracy in this CFT accounts for the black hole entropy. In the three-charge case (where triples of branes intersect at a point), the decoupled geometry contains an AdS_2 factor. Below a certain critical mass, the two-charge system displays solutions with naked timelike singularities even though they do not violate a BPS bound. We suggest a string theoretic resolution of these singularities.