{"title":"支点小调和Erdős-Hajnal猜想","authors":"James Davies","doi":"10.1016/j.jctb.2025.04.004","DOIUrl":null,"url":null,"abstract":"<div><div>We prove a conjecture of Kim and Oum that every proper pivot-minor-closed class of graphs has the strong Erdős-Hajnal property. More precisely, for every graph <em>H</em>, there exists <span><math><mi>ϵ</mi><mo>></mo><mn>0</mn></math></span> such that every <em>n</em>-vertex graph with no pivot-minor isomorphic to <em>H</em> contains two sets <span><math><mi>A</mi><mo>,</mo><mi>B</mi></math></span> of vertices such that <span><math><mo>|</mo><mi>A</mi><mo>|</mo><mo>,</mo><mo>|</mo><mi>B</mi><mo>|</mo><mo>⩾</mo><mi>ϵ</mi><mi>n</mi></math></span> and <em>A</em> is complete or anticomplete to <em>B</em>.</div></div>","PeriodicalId":54865,"journal":{"name":"Journal of Combinatorial Theory Series B","volume":"173 ","pages":"Pages 257-278"},"PeriodicalIF":1.2000,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Pivot-minors and the Erdős-Hajnal conjecture\",\"authors\":\"James Davies\",\"doi\":\"10.1016/j.jctb.2025.04.004\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>We prove a conjecture of Kim and Oum that every proper pivot-minor-closed class of graphs has the strong Erdős-Hajnal property. More precisely, for every graph <em>H</em>, there exists <span><math><mi>ϵ</mi><mo>></mo><mn>0</mn></math></span> such that every <em>n</em>-vertex graph with no pivot-minor isomorphic to <em>H</em> contains two sets <span><math><mi>A</mi><mo>,</mo><mi>B</mi></math></span> of vertices such that <span><math><mo>|</mo><mi>A</mi><mo>|</mo><mo>,</mo><mo>|</mo><mi>B</mi><mo>|</mo><mo>⩾</mo><mi>ϵ</mi><mi>n</mi></math></span> and <em>A</em> is complete or anticomplete to <em>B</em>.</div></div>\",\"PeriodicalId\":54865,\"journal\":{\"name\":\"Journal of Combinatorial Theory Series B\",\"volume\":\"173 \",\"pages\":\"Pages 257-278\"},\"PeriodicalIF\":1.2000,\"publicationDate\":\"2025-04-16\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Combinatorial Theory Series B\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0095895625000255\",\"RegionNum\":1,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Combinatorial Theory Series B","FirstCategoryId":"100","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0095895625000255","RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATHEMATICS","Score":null,"Total":0}
We prove a conjecture of Kim and Oum that every proper pivot-minor-closed class of graphs has the strong Erdős-Hajnal property. More precisely, for every graph H, there exists such that every n-vertex graph with no pivot-minor isomorphic to H contains two sets of vertices such that and A is complete or anticomplete to B.
期刊介绍:
The Journal of Combinatorial Theory publishes original mathematical research dealing with theoretical and physical aspects of the study of finite and discrete structures in all branches of science. Series B is concerned primarily with graph theory and matroid theory and is a valuable tool for mathematicians and computer scientists.