Gauge symmetry enhancement and N N = 2 supersymmetric quantum black holes in heterotic string vacua

Abstract

N = 2 supersymmetric quantum black holes in the heterotic S- T- U model are presented. In particular three classes of axion-free quantum black holes with half the N = 2, D = 4 supersymmetries unbroken are considered. First, these quantum black holes are investigated at generic points in moduli space. Then “linearized” non-abelian black holes are investigated representing a subset of non-abelian black hole solutions at critical points of perturbative gauge symmetry enhancement in moduli space. It is shown that the entropy of “linearized” non-abelian black holes can be obtained, starting at non-critical points in moduli space, by continuous variation of the moduli and a proper identification of the non-abelian charges.