无P_5$和无爪图中最长路径的非空交集

Paloma T. Lima, Amir Nikabadi
{"title":"无P_5$和无爪图中最长路径的非空交集","authors":"Paloma T. Lima, Amir Nikabadi","doi":"arxiv-2409.07366","DOIUrl":null,"url":null,"abstract":"A family $\\mathcal{F}$ of graphs is a \\textit{Gallai family} if for every\nconnected graph $G\\in \\mathcal{F}$, all longest paths in $G$ have a common\nvertex. While it is not known whether $P_5$-free graphs are a Gallai family,\nLong Jr., Milans, and Munaro [The Electronic Journal of Combinatorics, 2023]\nshowed that this is \\emph{not} the case for the class of claw-free graphs. We\ngive a complete characterization of the graphs $H$ of size at most five for\nwhich $(\\text{claw}, H)$-free graphs form a Gallai family. We also show that\n$(P_5, H)$-free graphs form a Gallai family if $H$ is a triangle, a paw, or a\ndiamond. Both of our results are constructive.","PeriodicalId":501407,"journal":{"name":"arXiv - MATH - Combinatorics","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Non-empty intersection of longest paths in $P_5$-free and claw-free graphs\",\"authors\":\"Paloma T. Lima, Amir Nikabadi\",\"doi\":\"arxiv-2409.07366\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"A family $\\\\mathcal{F}$ of graphs is a \\\\textit{Gallai family} if for every\\nconnected graph $G\\\\in \\\\mathcal{F}$, all longest paths in $G$ have a common\\nvertex. While it is not known whether $P_5$-free graphs are a Gallai family,\\nLong Jr., Milans, and Munaro [The Electronic Journal of Combinatorics, 2023]\\nshowed that this is \\\\emph{not} the case for the class of claw-free graphs. We\\ngive a complete characterization of the graphs $H$ of size at most five for\\nwhich $(\\\\text{claw}, H)$-free graphs form a Gallai family. We also show that\\n$(P_5, H)$-free graphs form a Gallai family if $H$ is a triangle, a paw, or a\\ndiamond. Both of our results are constructive.\",\"PeriodicalId\":501407,\"journal\":{\"name\":\"arXiv - MATH - Combinatorics\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-09-11\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"arXiv - MATH - Combinatorics\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/arxiv-2409.07366\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"arXiv - MATH - Combinatorics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/arxiv-2409.07366","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0

摘要

如果对于 \mathcal{F}$ 中的每一个连接图 $G$,$G$ 中所有最长路径都有一个共同顶点,那么这个图的 $mathcal{F}$ 族就是一个 \textit{Gallai 族}。虽然人们还不知道无 P_5$ 图是否是伽来族,但小龙、米兰斯和穆纳罗[The Electronic Journal of Combinatorics, 2023]的研究表明,无爪图类的情况并非如此。我们给出了大小最多为 5 的图 $H$ 的完整特征,对于这些图,$(\text{claw}, H)$free 图构成了一个伽来族。我们还证明,如果 $H$ 是三角形、爪形或菱形,则不含 $(P_5,H)$的图构成一个伽来族。我们的两个结果都是建设性的。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
Non-empty intersection of longest paths in $P_5$-free and claw-free graphs
A family $\mathcal{F}$ of graphs is a \textit{Gallai family} if for every connected graph $G\in \mathcal{F}$, all longest paths in $G$ have a common vertex. While it is not known whether $P_5$-free graphs are a Gallai family, Long Jr., Milans, and Munaro [The Electronic Journal of Combinatorics, 2023] showed that this is \emph{not} the case for the class of claw-free graphs. We give a complete characterization of the graphs $H$ of size at most five for which $(\text{claw}, H)$-free graphs form a Gallai family. We also show that $(P_5, H)$-free graphs form a Gallai family if $H$ is a triangle, a paw, or a diamond. Both of our results are constructive.
求助全文
通过发布文献求助,成功后即可免费获取论文全文。 去求助
来源期刊
自引率
0.00%
发文量
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信