Intersecting M-branes as Four-Dimensional Black Holes

TL;DR

This paper constructs specific intersecting brane solutions in 11D supergravity that, when compactified, produce four-dimensional extremal black holes with finite horizons, and discusses their entropy counting.

Contribution

It introduces new intersecting M-brane configurations that correspond to 4D black holes and proposes methods for counting their BPS degeneracy.

Findings

Constructed two explicit 1/8 supersymmetric intersecting brane solutions.

Reduced solutions to 4D extremal dyonic black holes with finite horizon area.

Suggested approaches for BPS state degeneracy counting matching black hole entropy.

Abstract

We present two 1/8 supersymmetric intersecting p-brane solutions of 11-dimensional supergravity which upon compactification to four dimensions reduce to extremal dyonic black holes with finite area of horizon. The first solution is a configuration of three intersecting 5-branes with an extra momentum flow along the common string. The second describes a system of two 2-branes and two 5-branes. Related (by compactification and T-duality) solution of type IIB theory corresponds to a completely symmetric configuration of four intersecting 3-branes. We suggest methods for counting the BPS degeneracy of three intersecting 5-branes which, in the macroscopic limit, reproduce the Bekenstein-Hawking entropy.