Gauge Symmetry Enhancement and 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.