The Bekenstein Formula and String Theory (N-brane Theory)

TL;DR

The paper surveys how string/M-theory branes, D-branes, M-branes, and Matrix theory account for black hole entropy by matching the Bekenstein-Hawking count with microscopic states. It develops the correspondence principle between brane-bound states and black holes, and presents precise entropy and emission/absorption matches for BPS and near-BPS black holes across dimensions, notably the D1–D5–P system and its 4D duals, while also exploring D-brane probes, Matrix theory, and AdS/CFT. It highlights successes, the role of fractionation, and the emergence of holographic dualities, while acknowledging unresolved issues such as information loss and the endpoint of Hawking evaporation. Together, these threads illustrate how brane/string degrees of freedom underpin black hole thermodynamics and how holographic ideas provide a powerful lens on quantum gravity.

Abstract

A review of recent progress in string theory concerning the Bekenstein formula for black hole entropy is given. Topics discussed include p-branes, D-branes and supersymmetry; the correspondence principle; the D- and M-brane approach to black hole entropy; the D-brane analogue of Hawking radiation, and information loss; D-branes as probes of black holes; and the Matrix theory approach to charged and neutral black holes. Some introductory material is included.