Extreme dyonic black holes in string theory

TL;DR

Tseytlin develops a conformal sigma-model framework to describe extreme dyonic black holes in toroidally compactified string theories as lower-dimensional images of wound solitonic strings. The throat region of these black holes is described by SL(2,R)×SU(2) WZW models with level κ tied to magnetic charges, enabling a direct counting of BPS-saturated string states that reproduces the Bekenstein-Hawking entropy in both D=4 and D=5, including rotating cases. The results establish a universal entropy duality: S_stat from microstate degeneracies matches S_BH = A/(4G_N), with precise matching factors, and reveal a magnetic renormalisation of string tension and a Regge-type bound on angular momentum arising from conformal invariance. The analysis highlights how short-distance hair encoded in throat CFTs governs black-hole microphysics and supports a consistent string-theoretic origin of black-hole entropy.

Abstract

Supersymmetric extreme dyonic black holes of toroidally compactified heterotic or type II string theory can be viewed as lower-dimensional images of solitonic strings wound around a compact dimension. We consider conformal sigma models which describe string configurations corresponding to various extreme dyonic black holes in four and five dimensions. These conformal models have regular short-distance region equivalent to a WZW theory with level proportional to magnetic charges. Arguments are presented suggesting a universal relation between the black hole entropy (area) and the statistical entropy of BPS-saturated oscillation states of solitonic string.[Extended version of a talk at the Workshop "Frontiers in Quantum Field Theory", in honor of the 60th birthday of K. Kikkawa (Osaka, Japan, 14-17 December 1995)]