Neighborhood perfect graphs
โ Scribed by J Lehel; Zs Tuza
- Publisher
- Elsevier Science
- Year
- 1986
- Tongue
- English
- Weight
- 595 KB
- Volume
- 61
- Category
- Article
- ISSN
- 0012-365X
No coin nor oath required. For personal study only.
โฆ Synopsis
The notion of neighborhood perfect graphs is introduced here as follows. Let G be a graph, ~N(G) denote the maximum number of edges such that no two of them belong to the same subgraph of G induced by the (closed) neighborhood of some vertex; let PN(G) be the minimum number of vertices whose neighborhood subgraphs cover the edge set of G. Then G is called neighborhood perfect if PN(G') = CrN(G' ) holds for every induced subgraph G' of G. It is expected that neighborhood perfect graphs are perfect also in the sense of Berge. We characterize here those chordal graphs which are neighborhood perfect. In addition, an algorithm to compute PN(G) = ON(G) is given for interval graphs.
๐ SIMILAR VOLUMES
We introduce the class of graphs such that every induced subgraph possesses a vertex whose neighbourhood can be split into a clique and a stable set. We prove that this class satisfies Berge's strong perfect graph conjecture. This class contains several well-known classes of (perfect) graphs and is
Let i be a positive integer. We generalize the chromatic number x ( G ) of G and the clique number w(G) of G as follows: The i-chromatic number of G , denoted by x Z ( G ) , is the least number k for which G has a vertex partition V,, V,, . . . , Vk: such that the clique number of the subgraph induc