{"title":"Approximate packing of independent transversals in locally sparse graphs","authors":"Debsoumya Chakraborti , Tuan Tran","doi":"10.1016/j.jctb.2025.07.005","DOIUrl":null,"url":null,"abstract":"<div><div>Fix <span><math><mi>ε</mi><mo>></mo><mn>0</mn></math></span> and consider a multipartite graph <em>G</em> with maximum degree at most <span><math><mo>(</mo><mn>1</mn><mo>−</mo><mi>ε</mi><mo>)</mo><mi>n</mi></math></span>, parts <span><math><msub><mrow><mi>V</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>,</mo><mo>…</mo><mo>,</mo><msub><mrow><mi>V</mi></mrow><mrow><mi>k</mi></mrow></msub></math></span> of the same size <em>n</em>, and where every vertex has at most <span><math><mi>o</mi><mo>(</mo><mi>n</mi><mo>)</mo></math></span> neighbors in any part <span><math><msub><mrow><mi>V</mi></mrow><mrow><mi>i</mi></mrow></msub></math></span>. Loh and Sudakov proved that any such <em>G</em> has an independent transversal. They further conjectured that the vertex set of <em>G</em> can be decomposed into pairwise disjoint independent transversals. In the present paper, we resolve this conjecture approximately by showing that <em>G</em> contains <span><math><mo>(</mo><mn>1</mn><mo>−</mo><mi>ε</mi><mo>)</mo><mi>n</mi></math></span> pairwise disjoint independent transversals. As applications, we give approximate answers to questions of Yuster, and of Fischer, Kühn, and Osthus.</div></div>","PeriodicalId":54865,"journal":{"name":"Journal of Combinatorial Theory Series B","volume":"175 ","pages":"Pages 187-212"},"PeriodicalIF":1.2000,"publicationDate":"2025-07-31","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/S009589562500053X","RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
Abstract
Fix and consider a multipartite graph G with maximum degree at most , parts of the same size n, and where every vertex has at most neighbors in any part . Loh and Sudakov proved that any such G has an independent transversal. They further conjectured that the vertex set of G can be decomposed into pairwise disjoint independent transversals. In the present paper, we resolve this conjecture approximately by showing that G contains pairwise disjoint independent transversals. As applications, we give approximate answers to questions of Yuster, and of Fischer, Kühn, and Osthus.
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.