Hairy Black Holes in String Theory

TL;DR

This paper constructs four-dimensional black hole solutions with axionic quantum hair in string theory, utilizing conformal field theory models, but notes their instability due to negative energy excitations.

Contribution

It introduces new black hole solutions with quantum hair in string theory using RG flows and coset CFTs, highlighting their properties and decay behavior.

Findings

Black hole solutions with axionic hair constructed

Solutions exhibit negative energy excitations

Expected to decay to vacuum

Abstract

Solutions of bosonic string theory are constructed which correspond to four-dimensional black holes with axionic quantum hair. The basic building blocks are the renormalization group flows of the CP1 model with a theta term and the SU(1,1)/U(1) WZW coset conformal field theory. However the solutions are also found to have negative energy excitations, and are accordingly expected to decay to the vacuum.