Kernels in directed graphs: a poison game
β Scribed by P. Duchet; H. Meyniel
- Publisher
- Elsevier Science
- Year
- 1993
- Tongue
- English
- Weight
- 282 KB
- Volume
- 115
- Category
- Article
- ISSN
- 0012-365X
No coin nor oath required. For personal study only.
β¦ Synopsis
We consider a two player game on a progressively and locally finite directed graph and we prove that the first player wins if and only if the graph has a local kernel. The result is sharp. From it, we derive a short proof of a general version of the Galeana-Sanchez & Neuman-Lara Theorem that give a sufficient condition for a digraph to be kernel-perfect.
π SIMILAR VOLUMES
In Section 1, we survey the existence theorems for a kernel; in Section 2, we discuss a new conjecture which could constitute a bridge between the kernel problems and the perfect graph conjecture. In fact, we believe that a graph is 'quasi-perfect' if and only if it is perfect. ## Proposition 1.1.
de Graaf, M., A. Schrijver and P.D. Seymour, Directed triangles in directed graphs, Discrete Mathematics 110 (1992) 279-282. h on n vertices, each with indegree and outdegree at least n/t, contains a directed circuit of length at most
We consider graphs that have a clique-cutset, and we show that this property preserves the existence of a kernel in a certain sense. We consider finite directed graphs that do not have multiple arcs or loops, but there may be symmetric arcs between some pairs of vertices. Let G = (V, A) be a direct
## Abstract Let __D__ be a directed graph of order 4__k__, where __k__ is a positive integer. Suppose that the minimum degree of __D__ is at least 6__k__βββ2. We show that __D__ contains __k__ disjoint directed quadrilaterals with only one exception. Β© 2005 Wiley Periodicals, Inc. J Graph Theory