Near-extremal black hole entropy and fluctuating 3-branes

TL;DR

This paper explores microscopic origins of black hole entropy in M-brane configurations, proposing that certain entropies are due to non-critical strings or 3-branes within 5-branes, advancing understanding of black hole microstates.

Contribution

It introduces a novel interpretation that 1-charge D=4 black hole entropy arises from 3-branes moving inside 5-branes, expanding the microscopic picture of black hole entropy.

Findings

Entropy for some configurations matches massless field theory predictions.

For 1-charge D=5 and 2-charge D=4 black holes, entropy is explained by a gas of non-critical strings at Hagedorn temperature.

Proposes 3-branes within 5-branes as the microscopic origin of entropy for certain D=4 black holes.

Abstract

We discuss the known microscopic interpretations of the Bekenstein-Hawking entropy for configurations of intersecting M-branes. In some cases the entropy scales as that of a massless field theory on the intersection. A different situation, found for configurations which reduce to 1-charge D=5 black holes or 2-charge D=4 black holes, is explained by a gas of non-critical strings at their Hagedorn temperature. We further suggest that the entropy of configurations reducing to 1-charge D=4 black holes is due to 3-branes moving within 5-branes.