{"title":"用k4的循环和细分来分离图的边","authors":"Fábio Botler, Tássio Naia","doi":"10.1002/jgt.23248","DOIUrl":null,"url":null,"abstract":"<div>\n \n <p>A <i>separating system</i> of a graph <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>G</mi>\n </mrow>\n </mrow>\n </semantics></math> is a family <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>S</mi>\n </mrow>\n </mrow>\n </semantics></math> of subgraphs of <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>G</mi>\n </mrow>\n </mrow>\n </semantics></math> for which the following holds: for all distinct edges <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>e</mi>\n </mrow>\n </mrow>\n </semantics></math> and <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>f</mi>\n </mrow>\n </mrow>\n </semantics></math> of <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>G</mi>\n </mrow>\n </mrow>\n </semantics></math>, there exists an element in <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>S</mi>\n </mrow>\n </mrow>\n </semantics></math> that contains <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>e</mi>\n </mrow>\n </mrow>\n </semantics></math> but not <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>f</mi>\n </mrow>\n </mrow>\n </semantics></math>. Recently, it has been shown that every graph of order <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>n</mi>\n </mrow>\n </mrow>\n </semantics></math> admits a separating system consisting of <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mn>19</mn>\n \n <mi>n</mi>\n </mrow>\n </mrow>\n </semantics></math> paths, improving the previous almost linear bound of <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>O</mi>\n \n <mrow>\n <mo>(</mo>\n \n <mi>n</mi>\n \n <msup>\n <mi>log</mi>\n \n <mo>⋆</mo>\n </msup>\n \n <mo> </mo>\n \n <mi>n</mi>\n \n <mo>)</mo>\n </mrow>\n </mrow>\n </mrow>\n </semantics></math>, and settling conjectures posed by Balogh, Csaba, Martin, and Pluhár and by Falgas-Ravry, Kittipassorn, Korándi, Letzter, and Narayanan. We investigate a natural generalization of these results to subdivisions of cliques, showing that every graph admits both a separating system consisting of <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mn>41</mn>\n \n <mi>n</mi>\n </mrow>\n </mrow>\n </semantics></math> edges and cycles and a separating system consisting of <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mn>82</mn>\n \n <mi>n</mi>\n </mrow>\n </mrow>\n </semantics></math> edges and subdivisions of <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <msub>\n <mi>K</mi>\n \n <mn>4</mn>\n </msub>\n </mrow>\n </mrow>\n </semantics></math>.</p>\n </div>","PeriodicalId":16014,"journal":{"name":"Journal of Graph Theory","volume":"110 1","pages":"41-47"},"PeriodicalIF":0.9000,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Separating the Edges of a Graph by Cycles and by Subdivisions of \\n \\n \\n \\n \\n K\\n 4\",\"authors\":\"Fábio Botler, Tássio Naia\",\"doi\":\"10.1002/jgt.23248\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div>\\n \\n <p>A <i>separating system</i> of a graph <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>G</mi>\\n </mrow>\\n </mrow>\\n </semantics></math> is a family <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>S</mi>\\n </mrow>\\n </mrow>\\n </semantics></math> of subgraphs of <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>G</mi>\\n </mrow>\\n </mrow>\\n </semantics></math> for which the following holds: for all distinct edges <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>e</mi>\\n </mrow>\\n </mrow>\\n </semantics></math> and <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>f</mi>\\n </mrow>\\n </mrow>\\n </semantics></math> of <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>G</mi>\\n </mrow>\\n </mrow>\\n </semantics></math>, there exists an element in <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>S</mi>\\n </mrow>\\n </mrow>\\n </semantics></math> that contains <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>e</mi>\\n </mrow>\\n </mrow>\\n </semantics></math> but not <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>f</mi>\\n </mrow>\\n </mrow>\\n </semantics></math>. Recently, it has been shown that every graph of order <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>n</mi>\\n </mrow>\\n </mrow>\\n </semantics></math> admits a separating system consisting of <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mn>19</mn>\\n \\n <mi>n</mi>\\n </mrow>\\n </mrow>\\n </semantics></math> paths, improving the previous almost linear bound of <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>O</mi>\\n \\n <mrow>\\n <mo>(</mo>\\n \\n <mi>n</mi>\\n \\n <msup>\\n <mi>log</mi>\\n \\n <mo>⋆</mo>\\n </msup>\\n \\n <mo> </mo>\\n \\n <mi>n</mi>\\n \\n <mo>)</mo>\\n </mrow>\\n </mrow>\\n </mrow>\\n </semantics></math>, and settling conjectures posed by Balogh, Csaba, Martin, and Pluhár and by Falgas-Ravry, Kittipassorn, Korándi, Letzter, and Narayanan. We investigate a natural generalization of these results to subdivisions of cliques, showing that every graph admits both a separating system consisting of <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mn>41</mn>\\n \\n <mi>n</mi>\\n </mrow>\\n </mrow>\\n </semantics></math> edges and cycles and a separating system consisting of <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mn>82</mn>\\n \\n <mi>n</mi>\\n </mrow>\\n </mrow>\\n </semantics></math> edges and subdivisions of <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <msub>\\n <mi>K</mi>\\n \\n <mn>4</mn>\\n </msub>\\n </mrow>\\n </mrow>\\n </semantics></math>.</p>\\n </div>\",\"PeriodicalId\":16014,\"journal\":{\"name\":\"Journal of Graph Theory\",\"volume\":\"110 1\",\"pages\":\"41-47\"},\"PeriodicalIF\":0.9000,\"publicationDate\":\"2025-04-10\",\"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.23248\",\"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.23248","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATHEMATICS","Score":null,"Total":0}
Separating the Edges of a Graph by Cycles and by Subdivisions of
K
4
A separating system of a graph is a family of subgraphs of for which the following holds: for all distinct edges and of , there exists an element in that contains but not . Recently, it has been shown that every graph of order admits a separating system consisting of paths, improving the previous almost linear bound of , and settling conjectures posed by Balogh, Csaba, Martin, and Pluhár and by Falgas-Ravry, Kittipassorn, Korándi, Letzter, and Narayanan. We investigate a natural generalization of these results to subdivisions of cliques, showing that every graph admits both a separating system consisting of edges and cycles and a separating system consisting of edges and subdivisions of .
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 .