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Related papers: Thompson's group F is not strongly amenable

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Generalizing Block and Weinberger's characterization of amenability we introduce the notion of uniformly finite homology for a group action on a compact space and use it to give a homological characterization of topological amenability for…

Group Theory · Mathematics 2010-12-14 Jacek Brodzki , Graham A. Niblo , Piotr Nowak , Nick J. Wright

Let $\Gamma$ be a finitely generated group which admits an action by homeomorphisms on a compact metrizable space $X$. We show that there is a metric on $X$ defining the original topology such that for this metric, the action is by…

Group Theory · Mathematics 2023-08-31 Ursula Hamenstädt

Let $\Gamma$ be an amenable countable discrete group. Fix an ergodic free nonsingular action of $\Gamma$ on a nonatomic standard probability space. Let $G$ be a compactly generated locally compact second countable group such that the…

Dynamical Systems · Mathematics 2019-09-04 Alexandre I. Danilenko

We reveal that Thompson's group $F$ has a quandle refinement, and we establish some essential results about the originating quandle.

Group Theory · Mathematics 2024-07-09 Markus Szymik

Let $M^{2d}$ be a compact symplectic manifold and $T$ a compact $n$-dimensional torus. A Hamiltonian action, $\tau$, of $T$ on $M$ is a GKM action if, for every $p \in M^T$, the isotropy representation of $T$ on $T_pM$ has pair-wise…

Symplectic Geometry · Mathematics 2007-05-23 Victor Guillemin , Tara S. Holm

This is the second of two papers but has been written so as to have minimal dependence on the first paper (which is also on this archive). Let G be a group and let M be a CAT(0) proper metric space (e.g. a simply connected complete…

Group Theory · Mathematics 2007-05-23 Robert Bieri , Ross Geoghegan

In this paper, we study isometric actions on finite-dimensional CAT(0) spaces for the Higman-Thompson groups $T_n$, which are generalizations of Thompson's group $T$. It is known that every semi-simple action of $T$ on a complete CAT(0)…

Group Theory · Mathematics 2023-08-25 Motoko Kato

In previous work, joint with Bux, Fluch, Marschler and Witzel, we proved that the braided Thompson groups are of type $\textrm{F}_\infty$. The proof utilized certain contractible cube complexes, which in this paper we prove are CAT(0). We…

Group Theory · Mathematics 2021-04-13 Matthew C. B. Zaremsky

We introduce a topometric version of Lipschitz-free spaces and study its universal property. Another aim of this paper is to investigate actions of topological groups $G$ on Lipschitz-free spaces $\mathcal{F}(M)$, induced by isometric…

Functional Analysis · Mathematics 2025-09-30 Michael Megrelishvili

In \cite{Kramer11} Kramer proves for a large class of semisimple Lie groups that they admit just one locally compact $\sigma$-compact Hausdorff topology compatible with the group operations. We present two different methods of generalising…

Group Theory · Mathematics 2014-11-06 Rupert McCallum

In this paper, we first prove the variational principle for amenable packing topological pressure. Then we obtain an inequality concerning amenable packing pressure for factor maps. Finally, we show that the equality about packing…

Dynamical Systems · Mathematics 2024-05-27 Ziqing Ding , Ercai Chen , Xiaoyao Zhou

Proper proximality of a countable group is a notion that was introduced by Boutonnet, Ioana and Peterson as a tool to study rigidity properties of certain von Neumann algebras associated to groups or ergodic group actions. In the present…

Group Theory · Mathematics 2022-06-03 Camille Horbez , Jingyin Huang , Jean Lécureux

We give the first examples of (non-amenable group) amenable actions on stably finite simple C*-algebras. More precisely, we give such actions for any countable group in an explicit way. The main ingredients of our construction are the full…

Operator Algebras · Mathematics 2026-02-09 Yuhei Suzuki

We construct an explicit infinite family of pairwise non-isomorphic infinite simple groups of type $\mathrm{F}_\infty$ (in particular, they are finitely presented) that act faithfully on the circle by orientation-preserving homeomorphisms,…

Group Theory · Mathematics 2025-12-23 Arnaud Brothier , Ryan Seelig

We prove that the elementary theory of Thompson's group $F$ is hereditarily undecidable.

Group Theory · Mathematics 2007-05-23 Vladimir Tolstykh , Valery Bardakov

Let G be a locally compact group, and ZL1(G) be the centre of its group algebra. We show that when $G$ is compact ZL1(G) is not amenable when G is either nonabelian and connected, or is a product of infinitely many finite nonabelian groups.…

Functional Analysis · Mathematics 2008-05-26 Ahmadreza Azimifard , Ebrahim Samei , Nico Spronk

We show that Thompson's group F occurs with great frequency in the group of PL homeomorphisms of the unit interval.

Group Theory · Mathematics 2013-09-04 Matthew G. Brin

The goal of this paper is to construct quasi-isometrically embedded subgroups of Thompson's group $F$ which are isomorphic to $\fz^n$ for all $n$. A result estimating the norm of an element of Thompson's group is found. As a corollary,…

Group Theory · Mathematics 2007-05-23 Jose Burillo

In this paper, we extend the notion of temporo-spatial differentiation problems to the setting of actions of more general topological groups. The problem can be expressed as follows: Given an action $T$ of an amenable discrete group $G$ on…

Dynamical Systems · Mathematics 2023-03-30 Aidan Young

We describe a family of words in Thompson's group F which present a challenge to the question of finding canonical minimal length representatives, and which show that F is not combable by geodesics. These words have the property that there…

Group Theory · Mathematics 2018-03-19 Sean Cleary , Jennifer Taback