{"title":"团并的最小饱和图","authors":"Wen-Han Zhu, Rong-Xia Hao, Zhen He","doi":"10.1016/j.disc.2025.114530","DOIUrl":null,"url":null,"abstract":"<div><div>Let <em>H</em> be a fixed graph. A graph <em>G</em> is called <em>H-saturated</em> if <em>G</em> does not contain a subgraph isomorphic to <em>H</em>, but the addition of any missing edge to <em>G</em> results in a copy of <em>H</em> in <em>G</em>. The <em>saturation number</em> of <em>H</em>, denoted <span><math><mi>s</mi><mi>a</mi><mi>t</mi><mo>(</mo><mi>n</mi><mo>,</mo><mi>H</mi><mo>)</mo></math></span>, is the minimum number of edges among all <em>H</em>-saturated graphs of order <em>n</em>, and <span><math><mi>S</mi><mi>a</mi><mi>t</mi><mo>(</mo><mi>n</mi><mo>,</mo><mi>H</mi><mo>)</mo></math></span> denotes the family of <em>H</em>-saturated graphs with <span><math><mi>s</mi><mi>a</mi><mi>t</mi><mo>(</mo><mi>n</mi><mo>,</mo><mi>H</mi><mo>)</mo></math></span> edges and <em>n</em> vertices. In this paper, we resolve a conjecture of Chen and Yuan (2024) <span><span>[4]</span></span> by determining <span><math><mi>S</mi><mi>a</mi><mi>t</mi><mo>(</mo><mi>n</mi><mo>,</mo><msub><mrow><mi>K</mi></mrow><mrow><mi>p</mi></mrow></msub><mo>∪</mo><mo>(</mo><mi>t</mi><mo>−</mo><mn>1</mn><mo>)</mo><msub><mrow><mi>K</mi></mrow><mrow><mi>q</mi></mrow></msub><mo>)</mo></math></span> for every <span><math><mi>q</mi><mo>≥</mo><mi>p</mi><mo>≥</mo><mn>2</mn></math></span> and <span><math><mi>t</mi><mo>≥</mo><mn>2</mn></math></span>.</div></div>","PeriodicalId":50572,"journal":{"name":"Discrete Mathematics","volume":"348 10","pages":"Article 114530"},"PeriodicalIF":0.7000,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Minimum saturated graphs for unions of cliques\",\"authors\":\"Wen-Han Zhu, Rong-Xia Hao, Zhen He\",\"doi\":\"10.1016/j.disc.2025.114530\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Let <em>H</em> be a fixed graph. A graph <em>G</em> is called <em>H-saturated</em> if <em>G</em> does not contain a subgraph isomorphic to <em>H</em>, but the addition of any missing edge to <em>G</em> results in a copy of <em>H</em> in <em>G</em>. The <em>saturation number</em> of <em>H</em>, denoted <span><math><mi>s</mi><mi>a</mi><mi>t</mi><mo>(</mo><mi>n</mi><mo>,</mo><mi>H</mi><mo>)</mo></math></span>, is the minimum number of edges among all <em>H</em>-saturated graphs of order <em>n</em>, and <span><math><mi>S</mi><mi>a</mi><mi>t</mi><mo>(</mo><mi>n</mi><mo>,</mo><mi>H</mi><mo>)</mo></math></span> denotes the family of <em>H</em>-saturated graphs with <span><math><mi>s</mi><mi>a</mi><mi>t</mi><mo>(</mo><mi>n</mi><mo>,</mo><mi>H</mi><mo>)</mo></math></span> edges and <em>n</em> vertices. In this paper, we resolve a conjecture of Chen and Yuan (2024) <span><span>[4]</span></span> by determining <span><math><mi>S</mi><mi>a</mi><mi>t</mi><mo>(</mo><mi>n</mi><mo>,</mo><msub><mrow><mi>K</mi></mrow><mrow><mi>p</mi></mrow></msub><mo>∪</mo><mo>(</mo><mi>t</mi><mo>−</mo><mn>1</mn><mo>)</mo><msub><mrow><mi>K</mi></mrow><mrow><mi>q</mi></mrow></msub><mo>)</mo></math></span> for every <span><math><mi>q</mi><mo>≥</mo><mi>p</mi><mo>≥</mo><mn>2</mn></math></span> and <span><math><mi>t</mi><mo>≥</mo><mn>2</mn></math></span>.</div></div>\",\"PeriodicalId\":50572,\"journal\":{\"name\":\"Discrete Mathematics\",\"volume\":\"348 10\",\"pages\":\"Article 114530\"},\"PeriodicalIF\":0.7000,\"publicationDate\":\"2025-04-11\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Discrete Mathematics\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0012365X25001384\",\"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":"Discrete Mathematics","FirstCategoryId":"100","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0012365X25001384","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATHEMATICS","Score":null,"Total":0}
Let H be a fixed graph. A graph G is called H-saturated if G does not contain a subgraph isomorphic to H, but the addition of any missing edge to G results in a copy of H in G. The saturation number of H, denoted , is the minimum number of edges among all H-saturated graphs of order n, and denotes the family of H-saturated graphs with edges and n vertices. In this paper, we resolve a conjecture of Chen and Yuan (2024) [4] by determining for every and .
期刊介绍:
Discrete Mathematics provides a common forum for significant research in many areas of discrete mathematics and combinatorics. Among the fields covered by Discrete Mathematics are graph and hypergraph theory, enumeration, coding theory, block designs, the combinatorics of partially ordered sets, extremal set theory, matroid theory, algebraic combinatorics, discrete geometry, matrices, and discrete probability theory.
Items in the journal include research articles (Contributions or Notes, depending on length) and survey/expository articles (Perspectives). Efforts are made to process the submission of Notes (short articles) quickly. The Perspectives section features expository articles accessible to a broad audience that cast new light or present unifying points of view on well-known or insufficiently-known topics.