Matrix Theory Description of Schwarzschild Black Holes in the Regime N ≫

We study the description of Schwarzschild black holes, of entropy S, within matrix theory in the regime N > ∼ S ≫ 1. We obtain the most general matrix theory equation of state by requiring that black holes admit a description within this theory. It has a recognisable form in various cases. In some cases a D dimensional black hole can plausibly be thought of as a D̃ = D + 1 dimensional black hole, described by another auxiliary matrix theory, but in its Ñ ∼ S regime. We find what appears to be a matrix theory generalisation to higher dynamical branes of the normalisation of dynamical string tension, seen in other contexts. We discuss a further possible generalisation of the matrix theory equation of state. In a special case, it is governed by N dynamical degrees of freedom. On leave of absence from Mehta Research Institute, Chhatnag Road, Jhusi, Allahabad 211 019, India.