Emission of charged particles from four- and five-dimensional black holes

TL;DR

This work extends the microscopic brane-based account of black hole thermodynamics by showing that charged scalar emission from near-extremal $D=5$ and $D=4$ black holes exactly reproduces the semiclassical Hawking radiation, including normalization and chemical potential effects. The authors formulate a multiply-wound intersection-string model, derive emission rates on the string side, and demonstrate precise agreement with gravity calculations for both the five- and four-dimensional cases. In 5D, the D1-D5-P system with KK momentum yields a long-string description with central charge $c=6$ that matches the $s$-wave charged emission rate, while in 4D a triply intersecting $5$-brane construction yields a comparable result, extended by a multiply-wound string with $L_{\rm eff}=n_1 n_2 n_3 L_1$. This supports a simple, robust microscopic picture of near-extremal Hawking radiation and clarifies the role of charge, chemical potential, and intersection-string fluctuations in black hole evaporation.

Abstract

Recently Das and Mathur found that the leading order Hawking emission rate of neutral scalars by near-extremal $D=5$ black holes is exactly reproduced by a string theoretic model involving intersecting D-branes. We show that the agreement continues to hold for charged scalar emission. We further show that similar agreement can be obtained for a class of near-extremal $D=4$ black holes using a model inspired by M-theory. In this model, BPS saturated $D=4$ black holes with four charges are realized in M-theory as 5-branes triply intersecting over a string. The low-energy excitations are signals traveling on the intersection string.