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 + \delta fraction of all edges, our algorithm finds an acyclic subgraph with 1/2 + \Omega (\delta /\log n) fraction of all edges.
Citation:
Moses Charikar, Konstantin Makarychev, Yury Makarychev, "On the Advantage over Random for Maximum Acyclic Subgraph," focs, pp.625-633, 48th Annual IEEE Symposium on Foundations of Computer Science (FOCS'07), 2007