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The groups which can act semisymmetrically on a cubic graph of twice odd order are determined modulo a normal subgroup which acts semiregularly on the vertices of the graph.

Group Theory · Mathematics 2007-05-23 Chris Parker

For every pair of vertices u and v with d(u; v) = n, Wun G v denotes the set of all vertices of G that are closer to u than to v. In this paper, we introduce quasi-({\lambda}; n)-distance-balanced graphs and then study some properties of…

Combinatorics · Mathematics 2019-09-09 Ehsan Pourhadi , Morteza Faghani

Two groups are virtually isomorphic if they can be obtained one from the other via a finite number of steps, where each step consists in taking a finite extension or a finite index subgroup (or viceversa). Virtually isomorphic groups are…

Geometric Topology · Mathematics 2016-02-15 Roberto Frigerio

We introduce the notion of graphical discreteness to group theory. A finitely generated group is graphically discrete if whenever it acts geometrically on a locally finite graph, the automorphism group of the graph is compact-by-discrete.…

Group Theory · Mathematics 2025-11-20 Alex Margolis , Sam Shepherd , Emily Stark , Daniel Woodhouse

An automorphism of a graph is called quasi-semiregular if it fixes a unique vertex of the graph and its remaining cycles have the same length. This kind of symmetry of graphs was first investigated by Kutnar, Malni\v{c}, Mart\'{i}nez and…

Combinatorics · Mathematics 2021-08-02 Fu-Gang Yin , Yan-Quan Feng , Jin-Xin Zhou , A-Hui Jia

This article lays the foundations for an analogue of geometric group theory that studies actions on graphs by right quasigroups, including racks and quandles. We study markings of graphs that realize racks, and we introduce (di)graph…

Geometric Topology · Mathematics 2026-04-01 Luc Ta

A quasi-tree is a geodesic metric space quasi-isometric to a tree. We give a general construction of many actions of groups on quasi-trees. The groups we can handle include non-elementary (relatively) hyperbolic groups, rank 1 CAT(0)…

Group Theory · Mathematics 2014-09-09 Mladen Bestvina , Kenneth Bromberg , Koji Fujiwara

A semiregular permutation group on a set $\Ome$ is called {\em bi-regular} if it has two orbits. A classification is given of quasiprimitive permutation groups with a biregular dihedral subgroup. This is then used to characterize the family…

Group Theory · Mathematics 2023-08-31 Jiangmin Pan , Fu-Gang Yin , Jin-Xin Zhou

We describe the structure of quasiflats in two-dimensio\-nal Artin groups. We rely on the notion of metric systolicity developed in our previous work. Using this weak form of non-positive curvature and analyzing in details the combinatorics…

Group Theory · Mathematics 2020-03-23 Jingyin Huang , Damian Osajda

We explore graph theoretical properties of minimal prime graphs of finite solvable groups. In finite group theory studying the prime graph of a group has been an important topic for the past almost half century. Recently prime graphs of…

Combinatorics · Mathematics 2020-11-23 Chris Florez , Jonathan Higgins , Kyle Huang , Thomas Michael Keller , Dawei Shen

We show that the fundamental groups of any two closed irreducible non-geometric graph-manifolds are quasi-isometric. This answers a question of Kapovich and Leeb. We also classify the quasi-isometry types of fundamental groups of…

Geometric Topology · Mathematics 2010-04-13 Jason A. Behrstock , Walter D. Neumann

The notion of almost centralizer and almost commutator are introduced and basic properties are established. They are used to study $\widetilde{\mathfrak M}\_c$-groups, i. e.groups for which every descending chain of centralizers each having…

Logic · Mathematics 2015-10-01 Nadja Hempel

We organize fundamental properties of quasi-Hamiltonian spaces on which a finite group acts, and we apply them to the theory of moduli spaces of flat connections on an oriented compact surface with boundary.

Symplectic Geometry · Mathematics 2025-12-23 Keito Takegoshi

The problem behind this paper is the proper measurement of the degree of quality/acceptability/distance to arbitrage of trades. We are narrowing the class of coherent acceptability indices introduced by Cherny and Madan (2007) by imposing…

Risk Management · Quantitative Finance 2011-04-05 Alexander Cherny , Damir Filipović

We introduce $C^*$-algebras associated with directed graphs, along with two generalizations of this concept, namely Exel-Pardo $C^*$-algebras associated with a self-similar action of a group on a directed graph, and the $C^*$-algebras…

Operator Algebras · Mathematics 2026-04-21 Pere Ara

The concept of a $\Gamma$-semigroup has been introduced by Mridul Kanti Sen in the Int. Symp., New Delhi, 1981. It is well known that the Green's relations play an essential role in studying the structure of semigroups. In the present paper…

General Mathematics · Mathematics 2017-04-19 Niovi Kehayopulu

We show that one can define and effectively compute Stallings graphs for quasi-convex subgroups of automatic groups (\textit{e.g.} hyperbolic groups or right-angled Artin groups). These Stallings graphs are finite labeled graphs, which are…

Group Theory · Mathematics 2018-01-03 Olga Kharlampovich , Alexei Miasnikov , Pascal Weil

The quasi-partition algebras were introduced by Daugherty and the first author as centralizers of the symmetric group. In this article, we give a more general definition of these algebras and give a construction of their simple modules. In…

Representation Theory · Mathematics 2023-08-14 Rosa Orellana , Nancy Wallace , Mike Zabrocki

Perhaps the fundamental theorem of geometric group theory, the Milnor--Schwarz lemma gives conditions under which the orbit map relating the geometry of a geodesic metric space and the word metric on a group acting isometrically on the…

Group Theory · Mathematics 2025-11-07 Robert Alonzo Lyman

We investigate the geometry of median metric spaces. The group-theoretic applications are towards Kazhdan's property (T) and Haagerup's property.

Group Theory · Mathematics 2008-09-25 Bogdan Nica