Abstract :
We study classical and quantum aspects of D = 4, N = 2 BPS black holes for T2 compactification of D = 6, N = 1 heterotic string vacua. We extend dynamical relaxation phenomena of moduli fields to a background consisting of a BPS soliton or a black hole and provide a simpler but more general derivation of the Ferrara-Kallosh extremized black hole mass and entropy. We study quantum effects to the BPS black hole mass spectra and to their dynamical relaxation. We show that, despite non-renormalizability of string effective supergravity, the quantum effect modifies BPS mass spectra only through coupling constant and moduli field renormalizations. Based on target-space duality, we establish a perturbative non-renormalization theorem and obtain the exact BPS black hole mass and entropy in terms of the renormalized string loop-counting parameter and renormalized moduli fields. We show that a similar conclusion holds, in the large T2 limit, for leading non-perturbative correction. We finally discuss implications to type-I and type-IIA Calabi-Yau black holes.
