English
Related papers

Related papers: Quasi-Random profinite groups

200 papers

We initiate the study of profinite groups of non-negative deficiency. The principal focus of the paper is to show that the existence of a finitely generated normal subgroup of infinite index in a profinite group $G$ of non-negative…

Group Theory · Mathematics 2011-06-23 Fritz Grunewald , Andrei Jaikin-Zapirain , Aline G. S. Pinto , Pavel A. Zalesski

We show that every closed normal subgroup of infinite index in a profinite surface group $\Gamma$ is contained in a semi-free profinite normal subgroup of $\Gamma$. This answers a question of Bary-Soroker, Stevenson, and Zalesskii.

Group Theory · Mathematics 2018-04-24 Matan Ginzburg , Mark Shusterman

Let $g$ be an element of a group $G$. For a positive integer $n$, let $E_n(g)$ be the subgroup generated by all commutators $[...[[x,g],g],\dots ,g]$ over $x\in G$, where $g$ is repeated $n$ times. We prove that if $G$ is a profinite group…

Group Theory · Mathematics 2016-06-02 E. I. Khukhro , P. Shumyatsky

The structure of finite and locally finite groups in which every element has prime power order (CP-groups) is well known. In this paper we note that the combination of our earlier results with the available information on the structure of…

Group Theory · Mathematics 2020-01-07 Pavel Shumyatsky

We introduce a class $\A$ of finitely generated residually finite accessible groups with some natural restriction on one-ended vertex groups in their JSJ-decompositions. We prove that the profinite completion of groups in $\A$ almost…

Group Theory · Mathematics 2022-08-30 Vagner R. de Bessa , Anderson L. P. Porto , Pavel A. Zalesskii

We show that, if $H$ is a random subgroup of a finitely generated free group $F_k$, only inner automorphisms of $F_k$ may leave $H$ invariant. A similar result holds for random subgroups of toral relatively hyperbolic groups, more generally…

Group Theory · Mathematics 2019-06-26 Vincent Guirardel , Gilbert Levitt

Just infinite groups play a significant role in profinite group theory. For each $c \geq 0$, we consider more generally JNN$_c$F profinite (or, in places, discrete) groups that are Fitting-free; these are the groups $G$ such that every…

Group Theory · Mathematics 2023-09-06 Benjamin Klopsch , Martyn Quick

We prove that the profinite completion of the fundamental group of a compact 3-manifold $M$ satisfies a Tits alternative: if a closed subgroup $H$ does not contain a free pro-$p$ subgroup for any $p$, then $H$ is virtually soluble, and…

Group Theory · Mathematics 2017-02-15 Henry Wilton , Pavel Zalesskii

A group $G$ is said to have restricted centralizers if for every $x\in G$ the centralizer $C_G(x)$ either is finite or has finite index in $G$. Shalev showed that a profinite group with restricted centralizers is virtually abelian. Here we…

Group Theory · Mathematics 2026-04-24 Cristina Acciarri , Pavel Shumyatsky

It is proved that the profinite completion of the mapping class group Mod (g,n) of a surface of genus g with n boundary components is isomorphic to such of the arithmetic group GL(6g-6+2n, Z). We establish a relation between the normal…

Number Theory · Mathematics 2020-04-10 Igor Nikolaev

We give a definition of weakly sofic groups (w-sofic groups). Our definition is rather natural extension of the definition of sofic groups where instead of Hamming metric on symmetric groups we use general bi-invariant metrics on finite…

Group Theory · Mathematics 2008-09-09 Lev Glebsky , Luis Manuel Rivera Martinez

In this paper, we analyze the behavior of various non-parametric local regression estimators, i.e. estimators that are based on local averaging, for estimating a Lipschitz regression function at a fixed point, or in sup-norm. We first prove…

Statistics Theory · Mathematics 2025-07-11 Jérémy Bettinger , François Portier , Adrien Saumard

Let $G$ be a finite group and let $p$ be a prime. In this paper, we study the structure of finite groups with a large number of $p$-regular conjugacy classes or, equivalently, a large number of irreducible $p$-modular representations. We…

Group Theory · Mathematics 2023-12-19 Christopher A. Schroeder

The hyperlinear profile of a group measures the growth rate of the dimension of unitary approximations to the group. We construct a finitely-presented group whose hyperlinear profile is at least subexponential, i.e. at least…

Group Theory · Mathematics 2018-06-15 William Slofstra

In this paper we compute the minimum degree of a faithful representation by partial transformations of a finite semigroup admitting a faithful completely reducible matrix representation over the field of complex numbers. This includes all…

Group Theory · Mathematics 2023-06-12 Stuart Margolis , Benjamin Steinberg

We define and study the class of positively finitely related (PFR) profinite groups. Positive finite relatedness is a probabilistic property of profinite groups which provides a first step to defining higher finiteness properties of…

Group Theory · Mathematics 2020-03-25 Steffen Kionke , Matteo Vannacci

Degree bounds for algebra generators of invariant rings are a topic of longstanding interest in invariant theory. We study the analogous question for field generators for the field of rational invariants of a representation of a finite…

Commutative Algebra · Mathematics 2024-06-17 Ben Blum-Smith , Thays Garcia , Rawin Hidalgo , Consuelo Rodriguez

We introduce the condition of a profinite group being semi-free, which is more general than being free and more restrictive than being quasi-free. In particular, every projective semi-free profinite group is free. We prove that the usual…

Group Theory · Mathematics 2010-04-02 Lior Bary-Soroker , Dan Haran , David Harbater

In this paper we discuss the existence of certain classes of cuspidal automorphic representations having non-zero Fourier coefficients for general semisimple algebraic group $G$ defined over a number field $k$ such that its Archimedean…

Number Theory · Mathematics 2015-05-27 Allen Moy , Goran Muić

Let $\mathbb{P}$ be an algebraic number field. We provide a computational analog of the strong approximation theorem for finitely generated Zariski dense groups $H\leq \mathrm{SL}(n,\mathbb{P})$, $n$ prime. That is, we present algorithms to…

Group Theory · Mathematics 2026-05-25 A. S. Detinko , D. L. Flannery , A. Hulpke