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Related papers: Limits of Thompson's group F

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Let T denote Thompson's group of piecewise 2-adic linear homeomorphisms of the circle. Ghys and Sergiescu showed that the rotation number of every element of T is rational, but their proof is very indirect. We give here a short, direct…

Dynamical Systems · Mathematics 2007-06-13 Danny Calegari

We present new metric criteria for non-amenability and discuss applications. The main application of the results of this paper is the proof of non-amenability of R.Thompson's group F. This is a continuation of the series of papers on our…

Group Theory · Mathematics 2013-12-23 Azer Akhmedov

We introduce a new method for computing the word length of an element of Thompson's group F with respect to a "consecutive" generating set of the form X_n={x_0,x_1,...,x_n}, which is a subset of the standard infinite generating set for F.…

Group Theory · Mathematics 2021-09-24 Matthew Horak , Melanie Stein , Jennifer Taback

A (discrete) group is called amenable whenever there exists a finitely additive right invariant probablity measure on it. For Thompson's group $F$ the problem whether it is amenable is a long-standing open question. We consider presentation…

Group Theory · Mathematics 2023-04-11 Victor Guba

Thompson's group $V$ has a rich variety of subgroups, containing all finite groups, all finitely generated free groups and all finitely generated abelian groups, the finitary permutation group of a countable set, as well as many wreath…

Group Theory · Mathematics 2020-09-29 José Burillo , Sean Cleary , Claas E. Röver

We discuss a central limit theorem in the framework of the group algebra of the Thompson group $F$. We consider the sequence of self-adjoint elements given by $a_n=\frac{g_n+g_n^{*}}{\sqrt{2}}$ in the noncommutative probability space…

Operator Algebras · Mathematics 2024-09-25 Arundhathi Krishnan

We introduce a refinement of bounded cohomology and prove that the suitable comparison homomorphisms vanish for an amenable group. We investigate in this context Thompson's group F and provide further evidence towards its amenability. We…

Group Theory · Mathematics 2025-12-23 Światosław R. Gal , Jarek Kędra

We describe the results of some computational explorations in Thompson's group F. We describe experiments to estimate the cogrowth of F with respect to its standard finite generating set, designed to address the subtle and difficult…

Group Theory · Mathematics 2018-03-19 Jose Burillo , Sean Cleary , Bert Wiest

Let $G$ be a finite group. We prove a theorem implying that the orders of elements of the holomorph $\operatorname{Hol}(G)$ are bounded from above by $|G|$, and we discuss an application to bounding automorphism orders of finite groups.

Group Theory · Mathematics 2015-10-08 Alexander Bors

We define half grid diagrams and prove every link is half grid presentable by constructing a canonical half grid pair (which gives rise to a grid diagram of some special type) associated with an element in the oriented Thompson group. We…

Geometric Topology · Mathematics 2024-08-21 Yangxiao Luo , Shunyu Wan

Recall that a group $G$ is said to be $\frac{3}{2}$-generated if every non-trivial element of $G$ belongs to a generating pair of $G$. Thompson's group $V$ was proved to be $\frac{3}{2}$-generated by Donoven and Harper in 2019. It was the…

Group Theory · Mathematics 2022-10-10 Gili Golan

We construct a family of infinite simple groups that we call \emph{twisted Brin-Thompson groups}, generalizing Brin's higher-dimensional Thompson groups $sV$ ($s\in\mathbb{N}$). We use twisted Brin-Thompson groups to prove a variety of…

Group Theory · Mathematics 2022-08-17 James Belk , Matthew C. B. Zaremsky

The purpose of this note is to prove a lower bound on the Folner function for Thompson's groups F.

Group Theory · Mathematics 2012-08-09 Justin Tatch Moore

We classify a large class of small groups of finite Morley rank: $N_\circ^\circ$-groups which are the infinite analogues of Thompson's $N$-groups. More precisely, we constrain the $2$-structure of groups of finite Morley rank containing a…

Group Theory · Mathematics 2016-10-05 Adrien Deloro , Eric Jaligot

The Lodha-Moore groups provide the first known examples of type F_\infty groups that are non-amenable and contain no non-abelian free subgroups. These groups are related to Thompson's group F in certain ways, for instance they contain it as…

Group Theory · Mathematics 2014-10-31 Matthew C. B. Zaremsky

In the space of marked group, we determine the structure of groups which are limit points of the set of all generalized quaternion groups.

Group Theory · Mathematics 2016-06-15 R. Hobbi , M. Shahryari

We prove that Thompson's group $F$ has a generating set with two elements such that every two powers of them generate a finite index subgroup of $F$.

Group Theory · Mathematics 2023-05-16 Gili Golan , Mark Sapir

Almost a decade ago Vaughan Jones introduced a method to produce knots from elements of the Thompson groups $F$, which was later extended to the Brown-Thompson group $F_3$. In this article we define a way to produce permutations out of…

Geometric Topology · Mathematics 2022-12-27 Valeriano Aiello , Stefano Iovieno

In this short note, we show that R. Thompson's group $F$ admits a normalish amenable subgroup, and that the standard copy of $F$ in R. Thompson's group $T$ is normalish in $T$. We further conjecture that if $F$ is non-amenable, then $T$…

Group Theory · Mathematics 2016-03-08 Collin Bleak

We investigate subgroups of the group PLo(I) of piecewise-linear, orientation-preserving homeomorphisms of the unit interval with finitely many breaks in slope, under the operation of composition, and also subgroups of the generalized…

Group Theory · Mathematics 2014-02-26 Collin Bleak