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Related papers: Automatic continuity of $\aleph_1$-free groups

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In [11] Sklinos proved that any uncountable free group is not $\aleph_1$-homogenenous. This was later generalized by Belegradek in [1] to torsion-free residually finite relatively free groups, leaving open whether the assumption of residual…

Logic · Mathematics 2025-02-12 Davide Carolillo , Gianluca Paolini

We prove that the reduced group C*-algebras of infinite countable discrete groups having topologically-free extreme boundaries, or more generally groups that satisfy certain combinatorial property including all acylindrically hyperbolic…

Operator Algebras · Mathematics 2026-04-27 Narutaka Ozawa

Sela proved every torsion-free one-ended hyperbolic group is coHopfian. We prove that there exist torsion-free one-ended hyperbolic groups that are not commensurably coHopfian. In particular, we show that the fundamental group of every…

Group Theory · Mathematics 2020-02-19 Emily Stark , Daniel J. Woodhouse

Solecki proved that the group of automorphisms of a countable structure cannot be an uncountable free abelian group. See more in Just, Shelah and Thomas math.LO/0003120 where as a by product we can say something on on uncountable…

Logic · Mathematics 2007-05-23 Saharon Shelah

We consider linear groups which do not contain unipotent elements of infinite order, which includes all linear groups in positive characteristic, and show that this class of groups has good properties which resemble those held by groups of…

Group Theory · Mathematics 2018-11-04 J. O. Button

We show that there exist non-unitarizable groups without non-abelian free subgroups. Both torsion and torsion free examples are constructed. As a by-product, we show that there exist finitely generated torsion groups with non-vanishing…

Group Theory · Mathematics 2009-02-15 D. Osin

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

We study groups having the property that every non-abelian subgroup is equal to its normalizer. This class of groups is closely related to an open problem posed by Berkovich. We give a full classification of finite groups having the above…

Group Theory · Mathematics 2016-10-21 Costantino Delizia , Urban Jezernik , Primoz Moravec , Chiara Nicotera

In this note, we show that an uncountable locally free group, and therefore every locally free group, has a free subgroup whose cardinality is the same as that of $G$. This result directly improve the main result in [T. Nishinaka,"Group…

Group Theory · Mathematics 2016-01-05 Tsunekazu Nishinaka

We show that (with one possible exception) there exist strongly dense free subgroups in any semisimple algebraic group over a large enough field. These are nonabelian free subgroups all of whose subgroups are either cyclic or Zariski dense.…

Group Theory · Mathematics 2011-03-28 Emmanuel Breuillard , Ben Green , Robert Guralnick , Terence Tao

For a torsion free finitely generated nilpotent group G we naturally associate four finite dimensional nilpotent Lie algebras over a field of characteristic zero. We show that if G is a relatively free group of some variery of nilpotent…

Group Theory · Mathematics 2009-03-10 C. Kofinas , V. Metaftsis , A. I. Papistas

We show that there is a countable universal abelian p-group for purity, i.e., a countable abelian p-group $U$ such that every countable abelian p-group purely embeds in $U$. This is the last result needed to provide a complete solution to…

Group Theory · Mathematics 2023-02-23 Ivo Herzog , Marcos Mazari-Armida

We provide characterizations of Lie groups as compact-like groups in which all closed zero-dimensional metric (compact) subgroups are discrete. The "compact-like" properties we consider include (local) compactness, (local)…

General Topology · Mathematics 2018-03-05 Dikran Dikranjan , Dmitri Shakhmatov

We will show that every element of a finitely generated abelian group is automorphically equivalent what we will define to be a {\em representative element} in a {\em repeat-free subgroup}, and for finite abelian groups we can count the…

Group Theory · Mathematics 2011-09-12 Charles F. Rocca

Elementarily free groups are the finitely generated groups with the same elementary theory as free groups. We prove that elementarily free groups are subgroup separable, answering a question of Zlil Sela.

Group Theory · Mathematics 2007-05-23 Henry Wilton

For a finite smooth algebraic group $F$ over a field $k$ and a smooth algebraic group $\bar G$ over the separable closure of $k$, we define the notion of $F$-kernel in $\bar G$ and we associate to it a set of nonabelian 2-cohomology. We use…

Group Theory · Mathematics 2018-06-04 Giancarlo Lucchini Arteche

Ancel, Dobrowolski, and Grabowski (Studia Math., 1994) proved that every countable discrete subgroup of the additive group of a normed space is free Abelian, hence isomorphic to the direct sum of a certain number of copies of the additive…

Functional Analysis · Mathematics 2024-08-07 Tomasz Kania , Ziemowit Kostana

We show that an infinite group $G$ definable in a $1$-h-minimal field admits a strictly $K$-differentiable structure with respect to which $G$ is a (weak) Lie group, and show that definable local subgroups sharing the same Lie algebra have…

Logic · Mathematics 2023-03-03 Juan Pablo Acosta , Assaf Hasson

In this note we prove the claim given in the title. A group G is noncommutatively slender if each map from the fundamental group of the Hawaiian Earring to G factors through projection to a canonical free subgroup. Graham Higman, in his…

Group Theory · Mathematics 2019-08-13 Samuel M. Corson

We prove that the abstract commensurator of a nonabelian free group, an infinite surface group, or more generally of a group that splits appropriately over a cyclic subgroup, is not finitely generated. This applies in particular to all…

Group Theory · Mathematics 2015-01-29 Laurent Bartholdi , Oleg Bogopolski