Title: Simply Exponential Approximation of the Permanent of Positive Semidefinite Matrices,
Abstract: We design a deterministic polynomial time $c^n$ approximation algorithm for
the permanent of positive semidefinite matrices where $c=e^{\gamma+1}\simeq
4.84$. We write a natural convex relaxation and show that its optimum solution
gives a $c^n$ approximation of the permanent. We further show that this factor
is asymptotically tight by constructing a family of positive semidefinite
matrices.