近似二方砖中的可移动边缘

IF 0.9 3区 数学 Q2 MATHEMATICS
Yipei Zhang, Fuliang Lu, Xiumei Wang, Jinjiang Yuan
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引用次数: 0

摘要

如果匹配覆盖图的边也是匹配覆盖的,那么它就是可移除的。可移除边的概念与洛瓦兹和普拉默提出的匹配覆盖图的耳分解有关。如果一个非双方格匹配覆盖图不存在非难紧切,那么它就是一个砖块图。Carvalho、Lucchesi 和 Murty 证明了除 和 之外的每个砖形图都至少有可移动边。如果有一对边使得砖块是一个双方匹配覆盖图,那么该砖块就是近双方图。在本文中,我们证明了在一个至少有六个顶点的近似二方图中,除了包含在两个互不相邻的三角形中的最多六个度数为三的顶点外,Ⅳ 的每个顶点都与最多两条不可移动的边相连;因此,至少有可移动的边。此外,所有达到这个下界的图都是有特征的。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
Removable edges in near‐bipartite bricks
An edge of a matching covered graph is removable if is also matching covered. The notion of removable edge arises in connection with ear decompositions of matching covered graphs introduced by Lovász and Plummer. A nonbipartite matching covered graph is a brick if it is free of nontrivial tight cuts. Carvalho, Lucchesi and Murty proved that every brick other than and has at least removable edges. A brick is near‐bipartite if it has a pair of edges such that is a bipartite matching covered graph. In this paper, we show that in a near‐bipartite brick with at least six vertices, every vertex of , except at most six vertices of degree three contained in two disjoint triangles, is incident with at most two nonremovable edges; consequently, has at least removable edges. Moreover, all graphs attaining this lower bound are characterized.
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来源期刊
Journal of Graph Theory
Journal of Graph Theory 数学-数学
CiteScore
1.60
自引率
22.20%
发文量
130
审稿时长
6-12 weeks
期刊介绍: The Journal of Graph Theory is devoted to a variety of topics in graph theory, such as structural results about graphs, graph algorithms with theoretical emphasis, and discrete optimization on graphs. The scope of the journal also includes related areas in combinatorics and the interaction of graph theory with other mathematical sciences. A subscription to the Journal of Graph Theory includes a subscription to the Journal of Combinatorial Designs .
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