4D black holes and holomorphic factorization of the 0A matrix model

In this letter, we relate the free energy of the 0A matrix model to the sumof topological and anti-topological string amplitudes. For arbitrary integermultiples of the matrix model self-dual radius we describe the geometry onwhich the corresponding topological string propagates. This geometry is not theone that follows from the usual ground ring analysis, but in a sense its"holomorphic square root". Mixing of terms for different genus in the matrixmodel free energy yields one-loop terms compatible with type II strings oncompact Calabi-Yau target spaces. As an application, we give an explicitexample of how to relate the 0A matrix model free energy to that of afour-dimensional black hole in type IIB theory, compactified on a compactCalabi-Yau. Variables, Legendre transforms, and large classical terms on bothsides match perfectly.Comment: 13 pages, minor correction