Approximation Algorithms for Label Cover and The Log-Density Threshold

Many known optimal NP-hardness of approximation results are reductions from a problem called Label-Cover. The input is a bipartite graph G = (L, R, E) and each edge e = (x, y) ∈ E carries a projection πe that maps labels to x to labels to y. The objective is to find a labeling of the vertices that satisfies as many of the projections as p...More