On finite totally $2$-closed groups

An abstract group $G$ is called totally $2$-closed if $H=H^{(2),\Omega }$ for any set $\Omega $ with $G\cong H\le \mathrm{Sym}(\Omega )$, where $H^{(2),\Omega }$ is the largest subgroup of $\mathrm{Sym}(\Omega )$ whose orbits on $\Omega \times \Omega $ are the same orbits of $H$. In this paper, we c...

Full description

Bibliographic Details
Main Authors: Abdollahi, Alireza, Arezoomand, Majid, Tracey, Gareth
Format: Article
Language:English
Published: Académie des sciences 2022-09-01
Series:Comptes Rendus. Mathématique
Online Access:https://comptes-rendus.academie-sciences.fr/mathematique/articles/10.5802/crmath.355/
_version_ 1797651489949220864
author Abdollahi, Alireza
Arezoomand, Majid
Tracey, Gareth
author_facet Abdollahi, Alireza
Arezoomand, Majid
Tracey, Gareth
author_sort Abdollahi, Alireza
collection DOAJ
description An abstract group $G$ is called totally $2$-closed if $H=H^{(2),\Omega }$ for any set $\Omega $ with $G\cong H\le \mathrm{Sym}(\Omega )$, where $H^{(2),\Omega }$ is the largest subgroup of $\mathrm{Sym}(\Omega )$ whose orbits on $\Omega \times \Omega $ are the same orbits of $H$. In this paper, we classify the finite soluble totally $2$-closed groups. We also prove that the Fitting subgroup of a totally $2$-closed group is a totally $2$-closed group. Finally, we prove that a finite insoluble totally $2$-closed group $G$ of minimal order with non-trivial Fitting subgroup has shape $Z\cdot X$, with $Z=Z(G)$ cyclic, and $X$ is a finite group with a unique minimal normal subgroup, which is nonabelian.
first_indexed 2024-03-11T16:16:33Z
format Article
id doaj.art-b1ecd228c77e408a95c30aca90dd2d30
institution Directory Open Access Journal
issn 1778-3569
language English
last_indexed 2024-03-11T16:16:33Z
publishDate 2022-09-01
publisher Académie des sciences
record_format Article
series Comptes Rendus. Mathématique
spelling doaj.art-b1ecd228c77e408a95c30aca90dd2d302023-10-24T14:19:34ZengAcadémie des sciencesComptes Rendus. Mathématique1778-35692022-09-01360G91001100810.5802/crmath.35510.5802/crmath.355On finite totally $2$-closed groupsAbdollahi, Alireza0Arezoomand, Majid1Tracey, Gareth2Department of Pure Mathematics, Faculty of Mathematics and Statistics, University of Isfahan, Isfahan 81746-73441, IranUniversity of Larestan, Larestan 74317-16137, IranSchool of Mathematics, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United KingdomAn abstract group $G$ is called totally $2$-closed if $H=H^{(2),\Omega }$ for any set $\Omega $ with $G\cong H\le \mathrm{Sym}(\Omega )$, where $H^{(2),\Omega }$ is the largest subgroup of $\mathrm{Sym}(\Omega )$ whose orbits on $\Omega \times \Omega $ are the same orbits of $H$. In this paper, we classify the finite soluble totally $2$-closed groups. We also prove that the Fitting subgroup of a totally $2$-closed group is a totally $2$-closed group. Finally, we prove that a finite insoluble totally $2$-closed group $G$ of minimal order with non-trivial Fitting subgroup has shape $Z\cdot X$, with $Z=Z(G)$ cyclic, and $X$ is a finite group with a unique minimal normal subgroup, which is nonabelian.https://comptes-rendus.academie-sciences.fr/mathematique/articles/10.5802/crmath.355/
spellingShingle Abdollahi, Alireza
Arezoomand, Majid
Tracey, Gareth
On finite totally $2$-closed groups
Comptes Rendus. Mathématique
title On finite totally $2$-closed groups
title_full On finite totally $2$-closed groups
title_fullStr On finite totally $2$-closed groups
title_full_unstemmed On finite totally $2$-closed groups
title_short On finite totally $2$-closed groups
title_sort on finite totally 2 closed groups
url https://comptes-rendus.academie-sciences.fr/mathematique/articles/10.5802/crmath.355/
work_keys_str_mv AT abdollahialireza onfinitetotally2closedgroups
AT arezoomandmajid onfinitetotally2closedgroups
AT traceygareth onfinitetotally2closedgroups