Packing r-Cliques in Weighted Chordal Graphs

In Hell et al. (2004), we have previously observed that, in a chordal graph G, the maximum number of independent r-cliques (i.e., of vertex disjoint subgraphs of G, each isomorphic to Kr , with no edges joining any two of the subgraphs) equals the minimum number of cliques of G that meet all the r-cliques of G. When r = 1, this says that chordal graphs have independence number equal to the clique covering number. When r = 2, this is equivalent to a result of Cameron (1989), and it implies a well known forbidden subgraph characterization of split graphs. In this paper we consider a weighted version of the above min-max optimization problem. Given a chordal graph G, with a nonnegative weight for each r-clique in G, we seek a set of independent r-cliques with maximum total weight. We present two algorithms to solve this problem, based on the principle of complementary slackness. The first one operates on a graph derived from G, and is an adaptation of an algorithm of Farber (1982). The se...

• Type: Journal
• Year: 2005
• Where: ANOR
• Authors: Pavol Hell, Sulamita Klein, Loana Tito Nogueira, Fábio Protti
• Keywords: ANOR 2005, Chordal Graph, Hell Et, Independent R-cliques