{"title":"稀疏伪随机图中近乎完美的派系因子","authors":"Jie Han , Yoshiharu Kohayakawa , Yury Person","doi":"10.1016/j.endm.2018.06.038","DOIUrl":null,"url":null,"abstract":"<div><p>We prove that, for any <span><math><mi>t</mi><mo>≥</mo><mn>3</mn></math></span>, there exists a constant <span><math><mi>c</mi><mo>=</mo><mi>c</mi><mo>(</mo><mi>t</mi><mo>)</mo><mo>></mo><mn>0</mn></math></span> such that any <em>d</em>-regular <em>n</em>-vertex graph with the second largest eigenvalue in absolute value <em>λ</em> satisfying <span><math><mi>λ</mi><mo>≤</mo><mi>c</mi><msup><mrow><mi>d</mi></mrow><mrow><mi>t</mi><mo>−</mo><mn>1</mn></mrow></msup><mo>/</mo><msup><mrow><mi>n</mi></mrow><mrow><mi>t</mi><mo>−</mo><mn>2</mn></mrow></msup></math></span> contains <span><math><mo>(</mo><mn>1</mn><mo>−</mo><mi>o</mi><mo>(</mo><mn>1</mn><mo>)</mo><mo>)</mo><mi>n</mi><mo>/</mo><mi>t</mi></math></span> vertex-disjoint copies of <span><math><msub><mrow><mi>K</mi></mrow><mrow><mi>t</mi></mrow></msub></math></span>. This provides further support for the conjecture of Krivelevich, Sudakov and Szábo [<em>Triangle factors in sparse pseudo-random graphs</em>, Combinatorica <strong>24</strong> (2004), pp. 403–426] that (<span><math><mi>n</mi><mo>,</mo><mi>d</mi><mo>,</mo><mi>λ</mi></math></span>)-graphs with <span><math><mi>n</mi><mo>∈</mo><mn>3</mn><mi>N</mi></math></span> and <span><math><mi>λ</mi><mo>≤</mo><mi>c</mi><msup><mrow><mi>d</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> for a suitably small absolute constant <span><math><mi>c</mi><mo>></mo><mn>0</mn></math></span> contain triangle-factors.</p></div>","PeriodicalId":35408,"journal":{"name":"Electronic Notes in Discrete Mathematics","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2018-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.endm.2018.06.038","citationCount":"7","resultStr":"{\"title\":\"Near-perfect clique-factors in sparse pseudorandom graphs\",\"authors\":\"Jie Han , Yoshiharu Kohayakawa , Yury Person\",\"doi\":\"10.1016/j.endm.2018.06.038\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>We prove that, for any <span><math><mi>t</mi><mo>≥</mo><mn>3</mn></math></span>, there exists a constant <span><math><mi>c</mi><mo>=</mo><mi>c</mi><mo>(</mo><mi>t</mi><mo>)</mo><mo>></mo><mn>0</mn></math></span> such that any <em>d</em>-regular <em>n</em>-vertex graph with the second largest eigenvalue in absolute value <em>λ</em> satisfying <span><math><mi>λ</mi><mo>≤</mo><mi>c</mi><msup><mrow><mi>d</mi></mrow><mrow><mi>t</mi><mo>−</mo><mn>1</mn></mrow></msup><mo>/</mo><msup><mrow><mi>n</mi></mrow><mrow><mi>t</mi><mo>−</mo><mn>2</mn></mrow></msup></math></span> contains <span><math><mo>(</mo><mn>1</mn><mo>−</mo><mi>o</mi><mo>(</mo><mn>1</mn><mo>)</mo><mo>)</mo><mi>n</mi><mo>/</mo><mi>t</mi></math></span> vertex-disjoint copies of <span><math><msub><mrow><mi>K</mi></mrow><mrow><mi>t</mi></mrow></msub></math></span>. This provides further support for the conjecture of Krivelevich, Sudakov and Szábo [<em>Triangle factors in sparse pseudo-random graphs</em>, Combinatorica <strong>24</strong> (2004), pp. 403–426] that (<span><math><mi>n</mi><mo>,</mo><mi>d</mi><mo>,</mo><mi>λ</mi></math></span>)-graphs with <span><math><mi>n</mi><mo>∈</mo><mn>3</mn><mi>N</mi></math></span> and <span><math><mi>λ</mi><mo>≤</mo><mi>c</mi><msup><mrow><mi>d</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> for a suitably small absolute constant <span><math><mi>c</mi><mo>></mo><mn>0</mn></math></span> contain triangle-factors.</p></div>\",\"PeriodicalId\":35408,\"journal\":{\"name\":\"Electronic Notes in Discrete Mathematics\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2018-07-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://sci-hub-pdf.com/10.1016/j.endm.2018.06.038\",\"citationCount\":\"7\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Electronic Notes in Discrete Mathematics\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S157106531830129X\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"Mathematics\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Electronic Notes in Discrete Mathematics","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S157106531830129X","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"Mathematics","Score":null,"Total":0}
引用次数: 7
摘要
我们证明了,对于任意t≥3,存在一个常数c=c(t)>0,使得任何d-正则n顶点图,其绝对值λ满足λ≤cdt−1/nt−2,其第二大特征值包含Kt的(1−o(1))个不相交的顶点拷贝。这进一步支持了Krivelevich, Sudakov和Szábo的猜想[稀疏伪随机图中的三角形因子,Combinatorica 24 (2004), pp. 403-426],即n∈3N且λ≤cd2的(n,d,λ)-图对于一个适当小的绝对常数c>0包含三角形因子。
Near-perfect clique-factors in sparse pseudorandom graphs
We prove that, for any , there exists a constant such that any d-regular n-vertex graph with the second largest eigenvalue in absolute value λ satisfying contains vertex-disjoint copies of . This provides further support for the conjecture of Krivelevich, Sudakov and Szábo [Triangle factors in sparse pseudo-random graphs, Combinatorica 24 (2004), pp. 403–426] that ()-graphs with and for a suitably small absolute constant contain triangle-factors.
期刊介绍:
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