{"title":"线性森林广义图兰数的稳定性","authors":"Yisai Xue, Yichong Liu, Liying Kang","doi":"10.1007/s00373-024-02781-w","DOIUrl":null,"url":null,"abstract":"<p>Given a graph <i>T</i> and a family of graphs <span>\\({\\mathcal {F}}\\)</span>, the generalized Turán number of <span>\\({\\mathcal {F}}\\)</span> is the maximum number of copies of <i>T</i> in an <span>\\({\\mathcal {F}}\\)</span>-free graph on <i>n</i> vertices, denoted by <span>\\(ex(n,T,{\\mathcal {F}})\\)</span>. A linear forest is a forest whose connected components are all paths and isolated vertices. Let <span>\\({\\mathcal {L}}_{k}\\)</span> be the family of all linear forests of size <i>k</i> without isolated vertices. In this paper, we obtained the maximum possible number of <i>r</i>-cliques in <i>G</i>, where <i>G</i> is <span>\\({\\mathcal {L}}_{k}\\)</span>-free with minimum degree at least <i>d</i>. Furthermore, we give a stability version of the result. As an application of the stability version of the result, we obtain a clique version of the stability of the Erdős–Gallai Theorem on matchings.</p>","PeriodicalId":12811,"journal":{"name":"Graphs and Combinatorics","volume":"87 1","pages":""},"PeriodicalIF":0.6000,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Stability of Generalized Turán Number for Linear Forests\",\"authors\":\"Yisai Xue, Yichong Liu, Liying Kang\",\"doi\":\"10.1007/s00373-024-02781-w\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>Given a graph <i>T</i> and a family of graphs <span>\\\\({\\\\mathcal {F}}\\\\)</span>, the generalized Turán number of <span>\\\\({\\\\mathcal {F}}\\\\)</span> is the maximum number of copies of <i>T</i> in an <span>\\\\({\\\\mathcal {F}}\\\\)</span>-free graph on <i>n</i> vertices, denoted by <span>\\\\(ex(n,T,{\\\\mathcal {F}})\\\\)</span>. A linear forest is a forest whose connected components are all paths and isolated vertices. Let <span>\\\\({\\\\mathcal {L}}_{k}\\\\)</span> be the family of all linear forests of size <i>k</i> without isolated vertices. In this paper, we obtained the maximum possible number of <i>r</i>-cliques in <i>G</i>, where <i>G</i> is <span>\\\\({\\\\mathcal {L}}_{k}\\\\)</span>-free with minimum degree at least <i>d</i>. Furthermore, we give a stability version of the result. As an application of the stability version of the result, we obtain a clique version of the stability of the Erdős–Gallai Theorem on matchings.</p>\",\"PeriodicalId\":12811,\"journal\":{\"name\":\"Graphs and Combinatorics\",\"volume\":\"87 1\",\"pages\":\"\"},\"PeriodicalIF\":0.6000,\"publicationDate\":\"2024-04-08\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Graphs and Combinatorics\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://doi.org/10.1007/s00373-024-02781-w\",\"RegionNum\":4,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Graphs and Combinatorics","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.1007/s00373-024-02781-w","RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
摘要
给定一个图 T 和一个图族 \({\mathcal{F}}\),\({\mathcal{F}}\)的广义图兰数就是在 n 个顶点上的无\({\mathcal{F}}\)图中 T 的最大副本数,用 \(ex(n,T,{\mathcal{F}})\)表示。线性森林是指其连通部分都是路径和孤立顶点的森林。设 \({\mathcal {L}}_{k}\) 是所有大小为 k 且没有孤立顶点的线性森林的族。在本文中,我们得到了 G 中 r-cliques 的最大可能数目,其中 G 是 \({\mathcal {L}}_{k}\)-free的,且最小度至少为 d。作为该结果稳定性版本的应用,我们得到了关于匹配的厄多斯-加莱定理稳定性的小块版本。
Stability of Generalized Turán Number for Linear Forests
Given a graph T and a family of graphs \({\mathcal {F}}\), the generalized Turán number of \({\mathcal {F}}\) is the maximum number of copies of T in an \({\mathcal {F}}\)-free graph on n vertices, denoted by \(ex(n,T,{\mathcal {F}})\). A linear forest is a forest whose connected components are all paths and isolated vertices. Let \({\mathcal {L}}_{k}\) be the family of all linear forests of size k without isolated vertices. In this paper, we obtained the maximum possible number of r-cliques in G, where G is \({\mathcal {L}}_{k}\)-free with minimum degree at least d. Furthermore, we give a stability version of the result. As an application of the stability version of the result, we obtain a clique version of the stability of the Erdős–Gallai Theorem on matchings.
期刊介绍:
Graphs and Combinatorics is an international journal devoted to research concerning all aspects of combinatorial mathematics. In addition to original research papers, the journal also features survey articles from authors invited by the editorial board.