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Related papers: Groups with exactly two conjugacy classes

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A proof of the Borel completeness of torsion free abelian groups is presented. This proof differs considerably from the approach of Paolini-Shelah.

Logic · Mathematics 2022-02-16 Michael C. Laskowski , Douglas S. Ulrich

We prove that the universal solenoid is the generic (in the sense of Baire category) connected compact metrizable abelian group. We also settle the dual problem in the sense of Pontryagin duality: $(\mathbb{Q},+)$, which is the dual of the…

Logic · Mathematics 2025-07-03 Udayan B. Darji , Márton Elekes , Tamás Kátay , Anett Kocsis , Máté Pálfy

Let F be an infinitely generated free group and R a fully invariant subgroup of F such that (a) R is contained in the commutator subgroup F' of F and (b) the quotient group F/R is residually torsion-free nilpotent. Then the automorphism…

Group Theory · Mathematics 2010-03-26 Vladimir Tolstykh

It is proved that generalized free product of two finite p-groups is a conjugacy p-separable group if and only if it is residually finite p-groups. This result is then applied to establish some sufficient conditions for conjugacy…

Group Theory · Mathematics 2011-11-30 E. A. Ivanova

We prove that the first order theory of nonabelian free groups eliminates the "there exists infinitely many" quantifier (in eq). Equivalently, since the theory of nonabelian free groups is stable, it does not have the finite cover property.…

Logic · Mathematics 2017-06-08 Rizos Sklinos

We consider left-invariant $G_2$-structures on $7$-dimensional almost Abelian Lie groups. Also, we characterise the associated torsion forms and the full torsion tensor according to the Lie bracket $A$ of the corresponding Lie algebra. In…

Differential Geometry · Mathematics 2023-10-25 Andrés J. Moreno

We prove that centralizers of elements in [f.g. free]-by-cyclic groups are computable. As a corollary we get that, given two conjugate elements in a [f.g. free]-by-cyclic group, the set of conjugators can be computed and that the conjugacy…

Group Theory · Mathematics 2023-10-16 André Carvalho

In this short article, we prove that any automorphism of the R. Thompson's group $F$ has infinitely many twisted conjugacy classes. The result follows from the work of Matthew Brin, together with a standard facts on R. Thompson's group $F$,…

Group Theory · Mathematics 2007-05-23 Collin Bleak , Alexander Fel'shtyn , Daciberg L. Gonçalves

We prove several results on products of conjugacy classes in finite simple groups. The first result is that there always exists a uniform generating triple. This result and other ideas are used to solve a 1966 conjecture of Peter Neumann…

Group Theory · Mathematics 2011-01-26 Robert Guralnick , Gunter Malle

Let G be a finite group. An element x in G is a real element if x is conjugate to its inverse in G. For x in G, the conjugacy class x^G is said to be a real conjugacy class if every element of x^G is real. We show that if 4 divides no real…

Group Theory · Mathematics 2013-06-28 Hung P. Tong-Viet

Conjugacy separability of any group of the class of one-relator groups given by the presentation $<a, b; [a^m,b^n]=1>$ ($m,n>1$) is proven.

Group Theory · Mathematics 2007-05-23 D. Tieudjo , D. I. Moldavanskii

It is proved that, for a prime $p>2$ and integer $n\geq 1$, finite $p$-groups of nilpotency class $3$ and having only two conjugacy class sizes $1$ and $p^n$ exist if and only if $n$ is even; moreover, for a given even positive integer,…

Group Theory · Mathematics 2017-08-15 Tushar Kanta Naik , Rahul Dattatraya Kitture , Manoj K. Yadav

The aim of this paper is to study the group of isomorphism classes of torsors of finite flat group schemes of rank 2 over a commutative ring $R$. This, in particular, generalises the group of quadratic algebras (free or projective), which…

Algebraic Geometry · Mathematics 2019-02-20 Ilia Pirashvili

We initiate the study of torsion-free algebraically hyperbolic groups; these groups generalise torsion-free hyperbolic groups and are intricately related to groups with no Baumslag--Solitar subgroups. Indeed, for groups of cohomological…

Group Theory · Mathematics 2025-04-29 Giles Gardam , Dawid Kielak , Alan D. Logan

We introduce the notion of a conjugation-free geometric presentation for a fundamental group of a line arrangement's complement, and we show that the fundamental groups of the following family of arrangements have a conjugation-free…

Geometric Topology · Mathematics 2010-03-17 Meital Eliyahu , David Garber , Mina Teicher

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

We use model theoretic forcing to prove that a generic countable torsion-free group does not admit any nontrivial locally moving action on a Hausdorff topological space, and yet admits a rich Rubin poset.

Group Theory · Mathematics 2025-12-03 Thomas Koberda , Yash Lodha

In this paper we study (logical) types and isotypical equivalence of torsion free Abelian groups. We describe all possible types of elements and standard 2-tuples of elements in these groups and classify separable torsion free Abelian…

Group Theory · Mathematics 2024-09-13 Elena Bunina

We describe all groups that can be generated by two twists along spherical sequences in an enhanced triangulated category. It will be shown that with one exception such a group is isomorphic to an abelian group generated by not more than…

Representation Theory · Mathematics 2019-11-28 Yury Volkov

We prove that every finitely generated group $G$ discriminated by a locally quasi-convex torsion-free hyperbolic group $\Gamma$ is effectively coherent: that is, presentations for finitely generated subgroups can be computed from the…

Group Theory · Mathematics 2014-12-12 Inna Bumagin , Jeremy Macdonald