Four Dimensional Black Holes in String Theory

TL;DR

This paper constructs exact four-dimensional black hole solutions in heterotic string theory, analyzes their spectra, and explores their deformations and singularity resolutions, revealing novel behaviors at small charge values.

Contribution

It introduces new string theory black hole solutions using orbifold and coset models, and investigates their spectrum, deformations, and potential singularity resolutions.

Findings

Identification of exact string theory black hole solutions.

Discovery of marginal operators deforming these solutions.

Observation of stable remnants at zero charge.

Abstract

Exact solutions of heterotic string theory corresponding to four-dimensional charge Q magnetic black holes are constructed as tensor products of an SU(2)/Z(2Q+2) WZW orbifold with a (0,1) supersymmetric SU(1,1)/U(1) WZW coset model. The spectrum is analyzed in some detail. ``Bad'' marginal operators are found which are argued to deform these theories to asymptotically flat black holes. Surprising behaviour is found for small values of Q, where low-energy field theory is inapplicable. At the minimal value Q=1, the theory degenerates. Renormalization group arguments are given that suggest the potential gravitational singularity of the low-energy field theory is resolved by a massive two-dimensional field theory. At Q=0, a stable, neutral ``remnant,'' of potential relevance to the black hole information paradox, is found.