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We describe various classes of infinitely presented groups that are condensation points in the space of marked groups. A well-known class of such groups consists of finitely generated groups admitting an infinite minimal presentation. We…

Group Theory · Mathematics 2019-02-20 Robert Bieri , Yves de Cornulier , Luc Guyot , Ralph Strebel

Given any finitely presented group G we find a triangular algebra such that has two presentations, one with fundamental group G and another with trivial group. Thus proving that given a collection G1,...,Gn of finitely presented groups…

Group Theory · Mathematics 2008-07-30 Jorge Nicolas Lopez

If a finite group G has a presentation with d generators and r relations, it is well-known that r - d is at least the rank of the Schur multiplier of G; a presentation is called efficient if equality holds. There is an analogous definition…

Group Theory · Mathematics 2009-05-05 R. M. Guralnick , W. M. Kantor , M. Kassabov , A. Lubotzky

The class of finitely presented algebras over a field $K$ with a set of generators $a_{1},..., a_{n}$ and defined by homogeneous relations of the form $a_{1}a_{2}... a_{n} =a_{\sigma (a)} a_{\sigma (2)} ... a_{\sigma (n)}$, where $\sigma$…

Rings and Algebras · Mathematics 2008-10-03 F. Cedo , E. Jespers , J. Okninksi

In this paper, we study matricial representations of certain finitely presented groups with N-generators of order-2. As an application, we consider a group algebra under our representations. Specifically, we characterize the inverses of all…

Representation Theory · Mathematics 2015-12-14 Ryan Golden , Ilwoo Cho

We construct examples of finitely generated groups L that have non-trivial actions on $\mathbb{R}$-trees but which cannot act, without fixing a vertex, on any simplicial tree. Moreover, any finitely presented group mapping onto L does have…

Group Theory · Mathematics 2013-06-19 Martin J. Dunwoody , Ashot Minasyan

Groups of finite type (also called finitely constrained groups), introduced by Grigorchuk, are known to be the closure of regular branch groups. This article explores many of their properties. Firstly, we prove that being finitely…

Group Theory · Mathematics 2025-09-05 Santiago Radi

Let $G$ be a finite solvable group. Then $G$ always has a useful presentation, which we call a "long presentation". Using a "long presentation" of $G$, we present an inductive method of constructing the irreducible representations of $G$…

Representation Theory · Mathematics 2018-10-11 Ravi S. Kulkarni , Soham Swadhin Pradhan

Extended affine Weyl groups are the Weyl groups of extended affine root systems. Finite presentations for extended affine Weyl groups are known only for nullities $\leq 2$, where for nullity 2 there is only one known such presentation. We…

Representation Theory · Mathematics 2007-05-23 Saeid Azam , Valiollah Shahsanaei

This paper surveys basic properties of finite presentation in groups, Lie algebras and rings. It includes some new results and also new, more elementary proofs, of some results that are already in the literature. In particular, we discuss…

Rings and Algebras · Mathematics 2019-10-29 Donald S. Passman , Lance W. Small

In this paper we study some algebraic properties of the rack structure as well as the representation theory of it, following the ideas given by M. Elhamdadi and E. M. Moutuou in \cite{Elhamdadi}. We establish a correspondence between the…

We consider groups defined by non-empty balanced presentations with the property that each relator is of the form R(x,y), where x and y are distinct generators and R(.,.) is determined by some fixed cyclically reduced word R(a,b) that…

Group Theory · Mathematics 2020-01-14 Johannes Cuno , Gerald Williams

In this note we look at presentations of subgroups of finitely presented groups with infinite cyclic quotients. We prove that if $H$ is a finitely generated normal subgroup of a finitely presented group $G$ with $G/H$ cyclic, then $H$ has…

Group Theory · Mathematics 2011-12-09 Mustafa Gokhan Benli

We describe an algorithm that computes the index of a finitely generated subgroup in a finitely $L$-presented group provided that this index is finite. This algorithm shows that the subgroup membership problem for finite index subgroups in…

Group Theory · Mathematics 2011-06-02 René Hartung

We prove a characterization of monomial projective representations of finitely generated nilpotent groups. We also characterize polycyclic groups whose projective representations are finite dimensional.

Representation Theory · Mathematics 2022-12-15 Sumana Hatui , E. K. Narayanan , Pooja Singla

In various classes of infinite groups, we identify groups that are presentable by products, i.e. groups having finite index subgroups which are quotients of products of two commuting infinite subgroups. The classes we discuss here include…

Group Theory · Mathematics 2017-01-13 P. de la Harpe , D. Kotschick

We give a new technique for constructing presentations by generators and relations for representations of groups like $SL_n(\mathbb{Z})$ and $Sp_{2g}(\mathbb{Z})$. Our results play an important role in recent work of the authors calculating…

Representation Theory · Mathematics 2025-04-02 Daniel Minahan , Andrew Putman

Let $G$ be a group. Then $S\subseteq G$ is an invariable generating set of $G$ if every subset $S'$ obtained from $S$ by replacing each element with a conjugate is also a generating set of $G$. We investigate invariable generation among key…

Group Theory · Mathematics 2025-05-29 Charles Garnet Cox , Anitha Thillaisundaram

We study natural linear representations of self-similar groups over finite fields. In particular, we show that if the group is generated by a finite automaton, then obtained matrices are automatic. This shows a new relation between two…

Group Theory · Mathematics 2014-09-18 R. Grigorchuk , Y. Leonov , V. Nekrashevych , V. Sushchansky

In this paper, we introduce the t-graphs defined on finitely-generate groups. We study some general aspects of the t-graphs on 2-generator groups, emphasising establishing necessary conditions for their connectedness. In particular, we…

Group Theory · Mathematics 2022-02-01 G. Diaz-Porto , I. S. Gutierrez , A. Torres-Grandisson