Let G = (V,E) be a finite undirected connected graph. We show that there is a common perfect elimination ordering of all powers of G which represent chordal graphs. Consequently, if G and all of its powers are chordal then all these graphs admit a common perfect elimination ordering. Such an orderin
LexBFS-orderings and powers of chordal graphs
✍ Scribed by Andreas Brandstädt; Feodor F. Dragan; Falk Nicolai
- Publisher
- Elsevier Science
- Year
- 1997
- Tongue
- English
- Weight
- 824 KB
- Volume
- 171
- Category
- Article
- ISSN
- 0012-365X
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✦ Synopsis
For an undirected graph G the kth power G k of G is the graph with the same vertex set as G where two vertices are adjacent iff their distance is at most k in G. In this paper we prove that any LexBFS-ordering of a chordal graph is a common perfect elimination ordering of all odd powers of this graph. Moreover, we characterize those chordal graphs by forbidden isometric subgraphs for which any LexBFS-ordering of the graph is a common perfect elimination ordering of all powers. For MCS-orderings of chordal graphs the situation is worse: even for trees MCS does not give a common perfect elimination ordering of powers.
📜 SIMILAR VOLUMES
The main theorem of this paper gives a forbidden induced subgraph condition on G that is sufficient for chordality of G m . This theorem is a generalization of a theorem of Balakrishnan and Paulraja who had provided this only for m = 2. We also give a forbidden subgraph condition on G that is suffi
We develop a constant time transposition "oracle" for the set of perfect elimination orderings of chordal graphs. Using this oracle, we can generate a Gray code of all perfect elimination orderings in constant amortized time using known results about antimatroids. Using clique trees, we show how the