A Graph with a Locally Projective Vertex-Transitive Group of Automorphisms Aut( $$Fi_{22}$$ ) Which Has a Nontrivial Stabilizer of a Ball of Radius $$2$$
{"title":"A Graph with a Locally Projective Vertex-Transitive Group of Automorphisms Aut( $$Fi_{22}$$ ) Which Has a Nontrivial Stabilizer of a Ball of Radius $$2$$","authors":"V. I. Trofimov","doi":"10.1134/s0081543823060238","DOIUrl":null,"url":null,"abstract":"<p>Earlier, to confirm that one of the possibilities for the structure of vertex stabilizers of graphs with projective suborbits is realizable, we announced the existence of a connected graph <span>\\(\\Gamma\\)</span> admitting a group of automorphisms <span>\\(G\\)</span> which is isomorphic to Aut<span>\\((Fi_{22})\\)</span> and has the following properties. First, the group <span>\\(G\\)</span> acts transitively on the set of vertices of <span>\\(\\Gamma\\)</span>, but intransitively on the set of <span>\\(3\\)</span>-arcs of <span>\\(\\Gamma\\)</span>. Second, the stabilizer in <span>\\(G\\)</span> of a vertex of <span>\\(\\Gamma\\)</span> induces on the neighborhood of this vertex a group <span>\\(PSL_{3}(3)\\)</span> in its natural doubly transitive action. Third, the pointwise stabilizer in <span>\\(G\\)</span> of a ball of radius 2 in <span>\\(\\Gamma\\)</span> is nontrivial. In this paper, we construct such a graph <span>\\(\\Gamma\\)</span> with <span>\\(G=\\mathrm{Aut}(\\Gamma)\\)</span>.\n</p>","PeriodicalId":0,"journal":{"name":"","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.1134/s0081543823060238","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Earlier, to confirm that one of the possibilities for the structure of vertex stabilizers of graphs with projective suborbits is realizable, we announced the existence of a connected graph \(\Gamma\) admitting a group of automorphisms \(G\) which is isomorphic to Aut\((Fi_{22})\) and has the following properties. First, the group \(G\) acts transitively on the set of vertices of \(\Gamma\), but intransitively on the set of \(3\)-arcs of \(\Gamma\). Second, the stabilizer in \(G\) of a vertex of \(\Gamma\) induces on the neighborhood of this vertex a group \(PSL_{3}(3)\) in its natural doubly transitive action. Third, the pointwise stabilizer in \(G\) of a ball of radius 2 in \(\Gamma\) is nontrivial. In this paper, we construct such a graph \(\Gamma\) with \(G=\mathrm{Aut}(\Gamma)\).