Probability for Primordial Black Holes in Higher Dimensional Universe

We investigate higher dimensional cosmological models in the semiclassical approximation with Hartle-Hawking Boundary conditions, assuming a gravitational action which is described by the scalar curvature with a cosmological constant. In the framework the probability for quantum creation of an inflationary universe with a pair of black holes in a multidimensional universe is evaluated. The probability for creation of a universe with a spatial section with $S^{1}XS^{D -2}$ topology is then compared with that of a higher dimensional de Sitter universe with $S^{D -1}$ spatial topology. It is found that a higher dimensional universe with a product space with primordial black holes pair is less probable to nucleate when the extra dimensions scale factors do not vary in an inflating universe.