In this paper we present a new approximation algorithm for the Max Acyclic Subgraph problem. Given an instance where the maximum acyclic subgraph contains 1/2 + δ fraction of all edges, our algorithm finds an acyclic subgraph with 1/2 + Ω(δ/ log n) fraction of all edges.
Moses Charikar, Konstantin Makarychev, Yury Makary