Black Holes and D-branes

TL;DR

The work demonstrates a precise microscopic accounting of the extremal black hole entropy in five dimensions by counting D1–D5–P bound states. It shows that the low-energy dynamics on the D1–D5 intersection is captured by a $(4,4)$ superconformal field theory with central charge $c=6 Q_1 Q_5$, yielding an extremal entropy $S=2\pi\sqrt{N Q_1 Q_5}$ consistent with the Bekenstein–Hawking value. In the near-extremal dilute-gas regime, left- and right-moving excitations reproduce the expected entropy $S=2\pi(\sqrt{N'_L}+\sqrt{N'_R})$ and the corresponding Hawking radiation rates, with greybody factors matching semiclassical cross-sections and a Hawking temperature $T_H$ that agrees across descriptions. The results provide a bridge between gravity and string theory microphysics, offering insights into black hole thermodynamics, information loss, and the role of D-brane dynamics in black hole entropy.

Abstract

D-branes have been used to describe many properties of extremal and near extremal black holes. These lecture notes provide a short review of these developments.