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Related papers: Residually finite non-exact groups

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We give an example of a finitely presented simple group containing a finitely generated subgroup which is not finitely presented.

Group Theory · Mathematics 2007-05-23 Diego Rattaggi

In this article we develop the theory of residually finite rationally $p$ (RFR$p$) groups, where $p$ is a prime. We first prove a series of results about the structure of finitely generated RFR$p$ groups (either for a single prime $p$, or…

Group Theory · Mathematics 2020-04-10 Thomas Koberda , Alexander I. Suciu

In this paper we explicitly compute finite bases of disjunctive identities and finite bases of regular representations for a number of interesting finite groups.

Group Theory · Mathematics 2009-09-25 Samuel Vovsi

We arrange classical small cancellation constructions to produce left-orderable groups: we show that every finitely generated group is the quotient of a left-ordered small cancellation group by a finitely generated kernel (Rips…

Group Theory · Mathematics 2024-01-30 Markus Steenbock

We establish a general criterion for the finite presentability of subdirect products of groups and use this to characterize finitely presented residually free groups. We prove that, for all $n\in\mathbb{N}$, a residually free group is of…

Group Theory · Mathematics 2008-09-23 Martin R. Bridson , James Howie , Charles F. Miller , Hamish Short

We prove that the isomorphism problem for finitely generated fully residually free groups is decidable. We also show that each finitely generated fully residually free group G has a decomposition that is invariant under automorphisms of G,…

Group Theory · Mathematics 2007-05-23 Inna Bumagin , Olga Kharlampovich , Alexei Miasnikov

We build quasi--isometry invariants of relatively hyperbolic groups which detect the hyperbolic parts of the group; these are variations of the stable dimension constructions previously introduced by the authors. We prove that, given any…

Group Theory · Mathematics 2016-09-19 Matthew Cordes , David Hume

We prove for residually finite groups the following long standing conjecture: the number of twisted conjugacy classes of an automorphism of a finitely generated group is equal (if it is finite) to the number of finite dimensional…

Group Theory · Mathematics 2012-05-01 Alexander Fel'shtyn , Evgenij Troitsky

We observe a criterion for groups to have vanishing virtual first Betti number and use it to give infinitely many examples of torsion-free, finitely generated, residually finite groups which aren't virtually diffuse. This answers a question…

Group Theory · Mathematics 2025-05-30 Andrew Ng

We construct examples of finitely generated infinite simple groups of homeomorphisms of the real line. Equivalently, these are examples of finitely generated simple left (or right) orderable groups. This answers a well known open question…

Group Theory · Mathematics 2019-10-02 James Hyde , Yash Lodha

We introduce the notion of residual finiteness for categories. In analogy with the group-theoretic setting, we prove that free categories and finitely generated subcategories of finite-dimensional vector spaces are residually finite.…

Category Theory · Mathematics 2019-03-28 Clara Loeh

A criterion for the HNN-extension of a finite p-group to be residually a finite p-group is obtained and based on this criterion the sufficient condition for residuality a finite p-group of HNN-extension with arbitrary base group is proved.…

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

If there is a non-residually finite hyperbolic group, then there is a non-residually finite rigid hyperbolic group.

Group Theory · Mathematics 2023-06-08 Xuzhi Tang

The first examples of formations which are arboreous (and therefore Hall) but not freely indexed (and therefore not locally extensible) are found. Likewise, the first examples of solvable formations which are freely indexed and arboreous…

Group Theory · Mathematics 2018-10-05 Karl Auinger , Alexander Bors

We use differential forms on loop spaces to prove that the fundamental group of certain geometric transformation groups is infinite. Examples include both finite and infinite dimensional Lie groups. The finite dimensional examples are the…

Differential Geometry · Mathematics 2025-10-03 Yoshiaki Maeda , Steven Rosenberg

We define a class of finite groups based on the properties of the closed twins of their power graphs and study the structure of those groups. As a byproduct, we obtain results about finite groups admitting a partition by cyclic subgroups.

Group Theory · Mathematics 2024-12-23 Daniela Bubboloni , Nicolas Pinzauti

We describe structure of locally finite groups of finite centraliser dimension.

Group Theory · Mathematics 2019-01-31 Alexandre Borovik , Ulla Karhumäki

We study fundamental groups of non compact Riemannian manifolds. We find conditions which ensure that the fundamental group is trivial, finite or finitely generated.

Differential Geometry · Mathematics 2007-05-23 Nader Yeganefar

In this paper it is shown how to construct a finite topological space $X$ for a given finitely presentable group $G$ such that $\pi_1(X)\cong G$. Our construction is not optimal in the sense that the cardinality of the space $X$ might not…

Algebraic Topology · Mathematics 2021-01-01 Samuel Roldán , Jose Luis Mora , Edward Becerra

Let $\mathcal G$ denote the space of finitely generated marked groups. For any finitely generated group $G$, we construct a continuous, injective map $f$ from the space of subgroups $Sub(G)$ to $\mathcal G$ that sends conjugate subgroups to…

Group Theory · Mathematics 2024-03-27 D. Osin