{"title":"循环商类型的立方因子不变图--交替情况","authors":"Brian Alspach , Primož Šparl","doi":"10.1016/j.ejc.2024.103964","DOIUrl":null,"url":null,"abstract":"<div><p>We investigate connected cubic vertex-transitive graphs whose edge sets admit a partition into a 2-factor <span><math><mi>C</mi></math></span> and a 1-factor that is invariant under a vertex-transitive subgroup of the automorphism group of the graph and where the quotient graph with respect to <span><math><mi>C</mi></math></span> is a cycle. There are two essentially different types of such cubic graphs. In this paper we focus on the examples of what we call the alternating type. We classify all such examples admitting a vertex-transitive subgroup of the automorphism group of the graph preserving the corresponding 2-factor and also determine the ones for which the 2-factor is invariant under the full automorphism group of the graph. In this way we introduce a new infinite family of cubic vertex-transitive graphs that is a natural generalization of the well-known generalized Petersen graphs as well as of the honeycomb toroidal graphs. The family contains an infinite subfamily of arc-regular examples and an infinite subfamily of 2-arc-regular examples.</p></div>","PeriodicalId":50490,"journal":{"name":"European Journal of Combinatorics","volume":null,"pages":null},"PeriodicalIF":1.0000,"publicationDate":"2024-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0195669824000490/pdfft?md5=9aafdb85196268b7bd37d9ff8366aa0b&pid=1-s2.0-S0195669824000490-main.pdf","citationCount":"0","resultStr":"{\"title\":\"Cubic factor-invariant graphs of cycle quotient type—The alternating case\",\"authors\":\"Brian Alspach , Primož Šparl\",\"doi\":\"10.1016/j.ejc.2024.103964\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>We investigate connected cubic vertex-transitive graphs whose edge sets admit a partition into a 2-factor <span><math><mi>C</mi></math></span> and a 1-factor that is invariant under a vertex-transitive subgroup of the automorphism group of the graph and where the quotient graph with respect to <span><math><mi>C</mi></math></span> is a cycle. There are two essentially different types of such cubic graphs. In this paper we focus on the examples of what we call the alternating type. We classify all such examples admitting a vertex-transitive subgroup of the automorphism group of the graph preserving the corresponding 2-factor and also determine the ones for which the 2-factor is invariant under the full automorphism group of the graph. In this way we introduce a new infinite family of cubic vertex-transitive graphs that is a natural generalization of the well-known generalized Petersen graphs as well as of the honeycomb toroidal graphs. The family contains an infinite subfamily of arc-regular examples and an infinite subfamily of 2-arc-regular examples.</p></div>\",\"PeriodicalId\":50490,\"journal\":{\"name\":\"European Journal of Combinatorics\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":1.0000,\"publicationDate\":\"2024-04-13\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.sciencedirect.com/science/article/pii/S0195669824000490/pdfft?md5=9aafdb85196268b7bd37d9ff8366aa0b&pid=1-s2.0-S0195669824000490-main.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"European Journal of Combinatorics\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0195669824000490\",\"RegionNum\":3,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"European Journal of Combinatorics","FirstCategoryId":"100","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0195669824000490","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
摘要
我们研究了连通的立方顶点传递图,这些图的边集可以划分为一个 2 因子 C 和一个 1 因子,后者在图的自动变形群的顶点传递子群下不变,并且相对于 C 的商图是一个循环。这种立方图有两种本质上不同的类型。在本文中,我们将重点讨论我们称之为交替类型的例子。我们会对所有这样的例子进行分类,这些例子中的图的自变群的顶点传递子群会保留相应的 2 因子,同时我们还会确定哪些例子的 2 因子在图的全自变群下是不变的。通过这种方法,我们引入了一个新的无穷立方顶点传递图族,它是著名的广义彼得森图和蜂巢环形图的自然概括。该族包含一个弧不规则的无限子族和一个2-弧不规则的无限子族。
Cubic factor-invariant graphs of cycle quotient type—The alternating case
We investigate connected cubic vertex-transitive graphs whose edge sets admit a partition into a 2-factor and a 1-factor that is invariant under a vertex-transitive subgroup of the automorphism group of the graph and where the quotient graph with respect to is a cycle. There are two essentially different types of such cubic graphs. In this paper we focus on the examples of what we call the alternating type. We classify all such examples admitting a vertex-transitive subgroup of the automorphism group of the graph preserving the corresponding 2-factor and also determine the ones for which the 2-factor is invariant under the full automorphism group of the graph. In this way we introduce a new infinite family of cubic vertex-transitive graphs that is a natural generalization of the well-known generalized Petersen graphs as well as of the honeycomb toroidal graphs. The family contains an infinite subfamily of arc-regular examples and an infinite subfamily of 2-arc-regular examples.
期刊介绍:
The European Journal of Combinatorics is a high standard, international, bimonthly journal of pure mathematics, specializing in theories arising from combinatorial problems. The journal is primarily open to papers dealing with mathematical structures within combinatorics and/or establishing direct links between combinatorics and other branches of mathematics and the theories of computing. The journal includes full-length research papers on important topics.