On the Black-Hole Conformal Field Theory Coupled to the Polyakov's String Theory. A Non Perturbative Analysis

TL;DR

This paper investigates the coupling of a 2D black-hole conformal field theory to a Euclidean bosonic string, analyzing the non-perturbative effects and showing the string susceptibility remains real across various dimensions.

Contribution

It provides a non-perturbative analysis of the coupled system, extending understanding of black-hole CFTs within string theory frameworks.

Findings

String susceptibility is real for all dimensions 0 to 4.

Coupling does not introduce non-physical (complex) susceptibilities.

Analysis supports the stability of the coupled system across dimensions.

Abstract

We couple the 2D black-hole conformal field theory discovered by Witten to a $D-1$ dimensional Euclidean bosonic string. We demonstrate that the resulting planar (=zero genus) string susceptibility is real for any $0\leq D \leq 4$.