  Let $A$ be an $n \times n$ positive definite Hermitian matrix with all
eigenvalues between 1 and 2. We represent the permanent of $A$ as the integral
of some explicit log-concave function on ${\Bbb R}^{2n}$. Consequently, there
is a fully polynomial randomized approximation scheme (FPRAS) for the permanent
of $A$.

Data Structures and Algorithms;Combinatorics