154 research outputs found
On edge-sets of bicliques in graphs
A biclique is a maximal induced complete bipartite subgraph of a graph. We
investigate the intersection structure of edge-sets of bicliques in a graph.
Specifically, we study the associated edge-biclique hypergraph whose hyperedges
are precisely the edge-sets of all bicliques. We characterize graphs whose
edge-biclique hypergraph is conformal (i.e., it is the clique hypergraph of its
2-section) by means of a single forbidden induced obstruction, the triangular
prism. Using this result, we characterize graphs whose edge-biclique hypergraph
is Helly and provide a polynomial time recognition algorithm. We further study
a hereditary version of this property and show that it also admits polynomial
time recognition, and, in fact, is characterized by a finite set of forbidden
induced subgraphs. We conclude by describing some interesting properties of the
2-section graph of the edge-biclique hypergraph.Comment: This version corrects an error in Theorem 11 found after the paper
went into prin
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