{"title":"$H$ free图中最长路径的非空交","authors":"James A. Long Jr., Kevin G. Milans, Andrea Munaro","doi":"10.37236/11277","DOIUrl":null,"url":null,"abstract":"We make progress toward a characterization of the graphs $H$ such that every connected $H$-free graph has a longest path transversal of size $1$. In particular, we show that the graphs $H$ on at most $4$ vertices satisfying this property are exactly the linear forests. We also show that if the order of a connected graph $G$ is large relative to its connectivity $\\kappa(G)$, and its independence number $\\alpha(G)$ satisfies $\\alpha(G) \\le \\kappa(G) + 2$, then each vertex of maximum degree forms a longest path transversal of size $1$.","PeriodicalId":11515,"journal":{"name":"Electronic Journal of Combinatorics","volume":"41 1","pages":"0"},"PeriodicalIF":0.7000,"publicationDate":"2023-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Non-Empty Intersection of Longest Paths in $H$-Free Graphs\",\"authors\":\"James A. Long Jr., Kevin G. Milans, Andrea Munaro\",\"doi\":\"10.37236/11277\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"We make progress toward a characterization of the graphs $H$ such that every connected $H$-free graph has a longest path transversal of size $1$. In particular, we show that the graphs $H$ on at most $4$ vertices satisfying this property are exactly the linear forests. We also show that if the order of a connected graph $G$ is large relative to its connectivity $\\\\kappa(G)$, and its independence number $\\\\alpha(G)$ satisfies $\\\\alpha(G) \\\\le \\\\kappa(G) + 2$, then each vertex of maximum degree forms a longest path transversal of size $1$.\",\"PeriodicalId\":11515,\"journal\":{\"name\":\"Electronic Journal of Combinatorics\",\"volume\":\"41 1\",\"pages\":\"0\"},\"PeriodicalIF\":0.7000,\"publicationDate\":\"2023-02-24\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Electronic Journal of Combinatorics\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.37236/11277\",\"RegionNum\":4,\"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":"Electronic Journal of Combinatorics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.37236/11277","RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATHEMATICS","Score":null,"Total":0}
Non-Empty Intersection of Longest Paths in $H$-Free Graphs
We make progress toward a characterization of the graphs $H$ such that every connected $H$-free graph has a longest path transversal of size $1$. In particular, we show that the graphs $H$ on at most $4$ vertices satisfying this property are exactly the linear forests. We also show that if the order of a connected graph $G$ is large relative to its connectivity $\kappa(G)$, and its independence number $\alpha(G)$ satisfies $\alpha(G) \le \kappa(G) + 2$, then each vertex of maximum degree forms a longest path transversal of size $1$.
期刊介绍:
The Electronic Journal of Combinatorics (E-JC) is a fully-refereed electronic journal with very high standards, publishing papers of substantial content and interest in all branches of discrete mathematics, including combinatorics, graph theory, and algorithms for combinatorial problems.