On Independent Sets and Bicliques in Graphs

• DOI: 10.1007/s00453-010-9474-1
• Publication Date: 2010-11-09T23:27:47Z
• Authors: Serge Gaspers; Dieter Kratsch; Mathieu Liedloff
• Keywords: Theory of computation

Bicliques of graphs have been studied extensively, partially motivated by the large number of applications. One of the main algorithmic interests is in designing algorithms to enumerate all maximal bicliques of a (bipartite) graph. Polynomial-time reductions have been used explicitly or implicitly to design polynomial delay algorithms to enumerate all maximal bicliques. Based on polynomial-time Turing reductions, various algorithmic problems on (maximal) bicliques can be studied by considering the related problem for (maximal) independent sets. In this line of research, we improve Prisner's upper bound on the number of maximal bicliques [Combinatorica, 2000] and show that the maximum number of maximal bicliques in a graph on $n$ vertices is exactly $3^{n/3}$ (up to a polynomial factor). The main results of this paper are $O(1.3642^n)$ time algorithms to compute the number of maximal independent sets and maximal bicliques in a graph.