Higher-dimensional resolution of dilatonic black-hole singularities

Abstract

We show that the four-dimensional extreme dilaton black hole with dilaton coupling constant $a= sqrt{p/(p+2)}$ can be interpreted as a {it completely non-singular}, non-dilatonic, black $p$-brane in $(4+p)$ dimensions provided that $p$ is {it odd}. Similar results are obtained for multi-black holes and dilatonic extended objects in higher spacetime dimensions. The non-singular black $p$-brane solutions include the self-dual three brane of ten-dimensional N=2B supergravity and a multi-fivebrane solution of eleven-dimensional supergravity. In the case of a supersymmetric non-dilatonic $p$-brane solution of a supergravity theory, we show that it saturates a bound on the energy per unit $p$-volume.