A biclique in a graph ? is a complete bipartite subgraph of ?. We give bounds for the maximum number of edges in a biclique in terms of the eigenvalues of matrix representations of ?. These bounds show a strong similarity with Lovasz's bound ?(?) for the Shannon capacity of ?. Motivated by this similarity we investigate bicliques and the bounds in certain product graphs.
['Willem H. Haemers']
Bicliques and Eigenvalues