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arXiv math/9911227math.CO
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关于$α$ -稳定图的结构

On the Structure of $α$-Stable Graphs

Vadim E. Levit, Eugen Mandrescu

摘要:

图G的稳定数是G的一个稳定系统(即G的最大尺寸的独立集)的基数。一个图是α-稳定的,如果它的稳定数在删除和添加任何边时保持相同。本文试图推广稳定树的一些性质,证明了不存在任何α-稳定弦图,并证明了:若G是连通二部图,则下列断言等价:G是α-稳定的,G可以表示为连通二部图的顶点不交并,每个连通二部图的顶点集恰有两个稳定系统覆盖; G有完美匹配且没有边属于它的所有完美匹配,从G的每个顶点发出至少两条包含在G的某些完美匹配中的边,G的任何顶点位于一个圈上,圈的边交替地在某些完美匹配中或不在某些完美匹配中;没有一个顶点属于G的所有稳定系统,也没有一条边属于G的所有完美匹配。

英文摘要:

The stability number of a graph G is the cardinality of a stability system of G (that is of a stable set of maximum size of G). A graph is alpha-stable if its stability number remains the same upon both the deletion and the addition of any edge. Trying to generalize some stable trees properties, we show that there does not exist any alpha-stable chordal graph, and we prove that: if G is a connected bipartite graph, then the following assertions are equivalent: G is alpha-stable; G can be written as a vertex disjoint union of connected bipartite graphs, each of them having exactly two stability systems covering its vertex set; G has perfect matchings and no edge belongs to all its perfect matchings; from each vertex of G are issuing at least two edges contained in some perfect matchings of G; any vertex of G lies on a cycle, whose edges are alternately in and not in some perfect matching; no vertex belongs to all stability systems of G, and no edge belongs to all its perfect matchings.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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