An LP-rounding 22-approximation for restricted maximum acyclic subgraph

In this paper we present a non-trivial LP-rounding algorithm for RMAS with approximation ratio 22≈2.828. Our result shows that, in order to prove a 4-hardness of approximation result for VP (if possible), one should consider reductions from harder problems. Alternatively, our approach might suggest a different way to design approximation algorithms for VP.