HIGHER-DIMENSIONAL RESOLUTION OF DILATONIC BLACK-HOLE SINGULARITIES

We show that the four-dimensional extreme dilaton black hole with dilaton coupling constant a = root p/(p+2) can be interpreted as a completely non-singular, non-dilatonic, black p-brane in (4 + p) dimensions provided that p is odd. Similar results are obtained for multiblack-holes and dilatonic extended objects in higher spacetime dimensions. The non-singular black p-brane solutions include the self-dual 3-brane of ten-dimensional N = 2B supergravity and a multi-5-brane 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 of all field configurations of appropriate asymptotic behaviour which are non-singular on some initial hypersurface.