Journal of Combinatorial Theory Series B最新文献_第10页

Disjointness graphs of short polygonal chains 多边形短链的不连续图

IF 1.4 1区数学

Journal of Combinatorial Theory Series B Pub Date : 2023-09-18 DOI: 10.1016/j.jctb.2023.08.008

János Pach , Gábor Tardos , Géza Tóth

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引用次数: 0

Entanglements 纠缠

IF 1.4 1区数学

Journal of Combinatorial Theory Series B Pub Date : 2023-09-13 DOI: 10.1016/j.jctb.2023.08.007

Johannes Carmesin , Jan Kurkofka

引用次数: 0

Strengthening Hadwiger's conjecture for 4- and 5-chromatic graphs 加强4-色图和5-色图的Hadwiger猜想

IF 1.4 1区数学

Journal of Combinatorial Theory Series B Pub Date : 2023-09-12 DOI: 10.1016/j.jctb.2023.08.009

Anders Martinsson, Raphael Steiner

引用次数: 0

Excluded minors are almost fragile II: Essential elements 被排除在外的未成年人几乎是脆弱的II：基本要素

IF 1.4 1区数学

Journal of Combinatorial Theory Series B Pub Date : 2023-09-04 DOI: 10.1016/j.jctb.2023.08.004

Nick Brettell , James Oxley , Charles Semple , Geoff Whittle

{"title":"Excluded minors are almost fragile II: Essential elements","authors":"Nick Brettell , James Oxley , Charles Semple , Geoff Whittle","doi":"10.1016/j.jctb.2023.08.004","DOIUrl":"https://doi.org/10.1016/j.jctb.2023.08.004","url":null,"abstract":"<div>Let M be an excluded minor for the class of <math><mi>P</mi></math>-representable matroids for some partial field <math><mi>P</mi></math>, let N be a 3-connected strong <math><mi>P</mi></math>-stabilizer that is non-binary, and suppose M has a pair of elements <math><mo>{</mo><mi>a</mi><mo>,</mo><mi>b</mi><mo>}</mo></math> such that <math><mi>M</mi><mo>﹨</mo><mi>a</mi><mo>,</mo><mi>b</mi></math> is 3-connected with an N-minor. Suppose also that <math><mo>|</mo><mi>E</mi><mo>(</mo><mi>M</mi><mo>)</mo><mo>|</mo><mo>≥</mo><mo>|</mo><mi>E</mi><mo>(</mo><mi>N</mi><mo>)</mo><mo>|</mo><mo>+</mo><mn>11</mn></math> and <math><mi>M</mi><mo>﹨</mo><mi>a</mi><mo>,</mo><mi>b</mi></math> is not N-fragile. In the prequel to this paper, we proved that <math><mi>M</mi><mo>﹨</mo><mi>a</mi><mo>,</mo><mi>b</mi></math> is at most five elements away from an N-fragile minor. An element e in a matroid <math><msup><mrow><mi>M</mi></mrow><mrow><mo>′</mo></mrow></msup></math> is N-essential if neither <math><msup><mrow><mi>M</mi></mrow><mrow><mo>′</mo></mrow></msup><mo>/</mo><mi>e</mi></math> nor <math><msup><mrow><mi>M</mi></mrow><mrow><mo>′</mo></mrow></msup><mo>﹨</mo><mi>e</mi></math> has an N-minor. In this paper, we prove that, under mild assumptions, <math><mi>M</mi><mo>﹨</mo><mi>a</mi><mo>,</mo><mi>b</mi></math> is one element away from a minor having at least <math><mi>r</mi><mo>(</mo><mi>M</mi><mo>)</mo><mo>−</mo><mn>2</mn></math> elements that are N-essential.</div>","PeriodicalId":54865,"journal":{"name":"Journal of Combinatorial Theory Series B","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50189165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Common graphs with arbitrary connectivity and chromatic number 具有任意连通性和色数的公共图

IF 1.4 1区数学

Journal of Combinatorial Theory Series B Pub Date : 2023-09-01 DOI: 10.1016/j.jctb.2023.06.001

Sejin Ko , Joonkyung Lee

引用次数: 6

The Ramsey number of a long even cycle versus a star 长偶周期与恒星的拉姆齐数

IF 1.4 1区数学

Journal of Combinatorial Theory Series B Pub Date : 2023-09-01 DOI: 10.1016/j.jctb.2023.05.001

Peter Allen , Tomasz Łuczak , Joanna Polcyn , Yanbo Zhang

引用次数: 0

List 4-colouring of planar graphs 列表4平面图的颜色

IF 1.4 1区数学

Journal of Combinatorial Theory Series B Pub Date : 2023-09-01 DOI: 10.1016/j.jctb.2023.04.001

Xuding Zhu

引用次数: 2

One-to-one correspondence between interpretations of the Tutte polynomials Tutte多项式解释之间的一一对应关系

IF 1.4 1区数学

Journal of Combinatorial Theory Series B Pub Date : 2023-09-01 DOI: 10.1016/j.jctb.2023.05.002

Martin Kochol

引用次数: 1

On Andreae's ubiquity conjecture 关于Andreae的普遍性猜想

IF 1.4 1区数学

Journal of Combinatorial Theory Series B Pub Date : 2023-09-01 DOI: 10.1016/j.jctb.2023.04.002

Johannes Carmesin

引用次数: 1

How to build a pillar: A proof of Thomassen's conjecture 如何建造支柱：托马森猜想的证明

IF 1.4 1区数学

Journal of Combinatorial Theory Series B Pub Date : 2023-09-01 DOI: 10.1016/j.jctb.2023.04.004

Irene Gil Fernández , Hong Liu

引用次数: 7