  In this letter, we relate the free energy of the 0A matrix model to the sum
of topological and anti-topological string amplitudes. For arbitrary integer
multiples of the matrix model self-dual radius we describe the geometry on
which the corresponding topological string propagates. This geometry is not the
one that follows from the usual ground ring analysis, but in a sense its
"holomorphic square root". Mixing of terms for different genus in the matrix
model free energy yields one-loop terms compatible with type II strings on
compact Calabi-Yau target spaces. As an application, we give an explicit
example of how to relate the 0A matrix model free energy to that of a
four-dimensional black hole in type IIB theory, compactified on a compact
Calabi-Yau. Variables, Legendre transforms, and large classical terms on both
sides match perfectly.
