Finding dense minors using average degree

IF 0.9 3区 数学 Q2 MATHEMATICS Journal of Graph Theory Pub Date : 2024-09-16 DOI:10.1002/jgt.23169
Kevin Hendrey, Sergey Norin, Raphael Steiner, Jérémie Turcotte
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Abstract

Motivated by Hadwiger's conjecture, we study the problem of finding the densest possible t -vertex minor in graphs of average degree at least t 1 . We show that if G has average degree at least t 1 , it contains a minor on t vertices with at least ( 2 1 o ( 1 ) ) t 2 edges. We show that this cannot be improved beyond 3 4 + o ( 1 ) t 2 . Finally, for t 6 we exactly determine the number of edges we are guaranteed to find in the densest t -vertex minor in graphs of average degree at least t 1 .

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利用平均程度查找密集的未成年人
受 Hadwiger 猜想的启发,我们研究了在平均度至少为 t - 1 的图中寻找最密集的 t 个顶点次要顶点的问题。我们证明,如果 G 的平均度至少为 t - 1,那么它包含了 t 个顶点上的 minor,其中至少有 ( 2 - 1 - o ( 1 ) t 2 条边。我们证明这一点不能超过 3 4 + o ( 1 ) t 2 。最后,对于 t ≤ 6,我们精确地确定了在平均阶数至少为 t - 1 的图中,我们保证能在最密集的 t 个顶点次要图中找到的边的数量。
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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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