{"title":"关于图的最小等分","authors":"Jianfeng Hou, Shufei Wu","doi":"10.1002/jgt.23284","DOIUrl":null,"url":null,"abstract":"<div>\n \n <p>A bisection of a graph is a bipartition of its vertex set in which the number of vertices in the two parts differ by at most 1, and its size is the number of edges which go across the two parts. Let <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>G</mi>\n </mrow>\n </mrow>\n </semantics></math> be a graph with <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>n</mi>\n </mrow>\n </mrow>\n </semantics></math> vertices and <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>m</mi>\n </mrow>\n </mrow>\n </semantics></math> edges. Bollobás and Scott asked the following: What are the largest and smallest cuts that we can guarantee with bisections of <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>G</mi>\n </mrow>\n </mrow>\n </semantics></math>? There are reasonable sufficient conditions such that <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>G</mi>\n </mrow>\n </mrow>\n </semantics></math> has bisections of size at least <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>m</mi>\n \n <mo>/</mo>\n \n <mn>2</mn>\n \n <mo>+</mo>\n \n <mi>c</mi>\n \n <mi>n</mi>\n </mrow>\n </mrow>\n </semantics></math> for some <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>c</mi>\n \n <mo>></mo>\n \n <mn>0</mn>\n </mrow>\n </mrow>\n </semantics></math>. In this paper, we study the Min-Bisection problem which has arisen in numerous contexts, and initially give some sufficient conditions such that <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>G</mi>\n </mrow>\n </mrow>\n </semantics></math> has bisections of size at most <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>m</mi>\n \n <mo>/</mo>\n \n <mn>2</mn>\n \n <mo>−</mo>\n \n <mi>c</mi>\n \n <mi>n</mi>\n </mrow>\n </mrow>\n </semantics></math> for some <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>c</mi>\n \n <mo>></mo>\n \n <mn>0</mn>\n </mrow>\n </mrow>\n </semantics></math>.</p>\n </div>","PeriodicalId":16014,"journal":{"name":"Journal of Graph Theory","volume":"110 4","pages":"437-447"},"PeriodicalIF":1.0000,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"On Min-Bisections of Graphs\",\"authors\":\"Jianfeng Hou, Shufei Wu\",\"doi\":\"10.1002/jgt.23284\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div>\\n \\n <p>A bisection of a graph is a bipartition of its vertex set in which the number of vertices in the two parts differ by at most 1, and its size is the number of edges which go across the two parts. Let <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>G</mi>\\n </mrow>\\n </mrow>\\n </semantics></math> be a graph with <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>n</mi>\\n </mrow>\\n </mrow>\\n </semantics></math> vertices and <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>m</mi>\\n </mrow>\\n </mrow>\\n </semantics></math> edges. Bollobás and Scott asked the following: What are the largest and smallest cuts that we can guarantee with bisections of <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>G</mi>\\n </mrow>\\n </mrow>\\n </semantics></math>? There are reasonable sufficient conditions such that <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>G</mi>\\n </mrow>\\n </mrow>\\n </semantics></math> has bisections of size at least <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>m</mi>\\n \\n <mo>/</mo>\\n \\n <mn>2</mn>\\n \\n <mo>+</mo>\\n \\n <mi>c</mi>\\n \\n <mi>n</mi>\\n </mrow>\\n </mrow>\\n </semantics></math> for some <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>c</mi>\\n \\n <mo>></mo>\\n \\n <mn>0</mn>\\n </mrow>\\n </mrow>\\n </semantics></math>. In this paper, we study the Min-Bisection problem which has arisen in numerous contexts, and initially give some sufficient conditions such that <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>G</mi>\\n </mrow>\\n </mrow>\\n </semantics></math> has bisections of size at most <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>m</mi>\\n \\n <mo>/</mo>\\n \\n <mn>2</mn>\\n \\n <mo>−</mo>\\n \\n <mi>c</mi>\\n \\n <mi>n</mi>\\n </mrow>\\n </mrow>\\n </semantics></math> for some <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>c</mi>\\n \\n <mo>></mo>\\n \\n <mn>0</mn>\\n </mrow>\\n </mrow>\\n </semantics></math>.</p>\\n </div>\",\"PeriodicalId\":16014,\"journal\":{\"name\":\"Journal of Graph Theory\",\"volume\":\"110 4\",\"pages\":\"437-447\"},\"PeriodicalIF\":1.0000,\"publicationDate\":\"2025-07-21\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Graph Theory\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1002/jgt.23284\",\"RegionNum\":3,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Graph Theory","FirstCategoryId":"100","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/jgt.23284","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATHEMATICS","Score":null,"Total":0}
A bisection of a graph is a bipartition of its vertex set in which the number of vertices in the two parts differ by at most 1, and its size is the number of edges which go across the two parts. Let be a graph with vertices and edges. Bollobás and Scott asked the following: What are the largest and smallest cuts that we can guarantee with bisections of ? There are reasonable sufficient conditions such that has bisections of size at least for some . In this paper, we study the Min-Bisection problem which has arisen in numerous contexts, and initially give some sufficient conditions such that has bisections of size at most for some .
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 .