An FPTAS for minimizing a class of low-rank quasi-concave functions over a convex set.

We consider the problem of minimizing a class of quasi-concave functions over a convex set. Quasi-concave functions are generalizations of concave functions and NP-hard to minimize in general. We present a simple fully polynomial time approximation scheme (FPTAS) for minimizing a class of low-rank quasi-concave functions. Our algorithm solves a polynomial number of linear minimization problems and computes an extreme point near-optimal solution. Therefore, it applies directly to combinatorial 0-1 problems where the convex hull of feasible solutions is known.