Gauge Theory Description of D-brane Black Holes: Emergence of the Effective SCFT and Hawking Radiation

TL;DR

This paper derives an effective superconformal field theory (SCFT) description of near extremal 5D black holes modeled by D1- and D5-branes, explaining Hawking radiation and supporting the consistency of string theory in black hole physics.

Contribution

It presents a new derivation of the effective SCFT for D-brane black holes and explains the emergence of Hawking radiation from string interactions.

Findings

Effective c=6, N=4 SCFT describes near extremal black holes.

Coupling to minimal scalars induces Hawking radiation.

Supports the validity of string theory in black hole thermodynamics.

Abstract

We study the hypermultiplet moduli space of an N=4, U(Q_1)xU(Q_5) gauge theory in 1+1 dimensions to extract the effective SCFT description of near extremal 5-dimensional black holes modelled by a collection of D1- and D5-branes. On the moduli space, excitations with fractional momenta arise due to a residual discrete gauge invariance. It is argued that, in the infra-red, the lowest energy excitations are described by an effective c=6, N=4 SCFT on T^4, also valid in the large black hole regime. The ``effective string tension'' is obtained using T-duality covariance. While at the microscopic level, minimal scalars do not couple to (1,5) strings, in the effective theory a coupling is induced by (1,1) and (5,5) strings, leading to Hawking radiation. These considerations imply that, at least for such black holes, the calculation of the Hawking decay rate for minimal scalars has a sound foundation in string theory and statistical mechanics and, hence, there is no information loss.