English
Related papers

Related papers: Geometric structures related to the braided Thomps…

200 papers

We prove that the braided Thompson's groups $V_{\rm br}$ and $F_{\rm br}$ are of type $F_\infty$, confirming a conjecture by John Meier. The proof involves showing that matching complexes of arcs on surfaces are highly connected. In an…

Group Theory · Mathematics 2021-06-23 Kai-Uwe Bux , Martin Fluch , Marco Marschler , Stefan Witzel , Matthew C. B. Zaremsky

We construct braided versions $sV_{br}$ of the Brin-Thompson groups $sV$ and prove that they are of type $F_\infty$. The proof involves showing that the matching complexes of colored arcs on surfaces are highly connected.

Group Theory · Mathematics 2021-01-12 Robert Spahn

This article is dedicated to the study of asymptotically rigid mapping class groups of infinitely-punctured surfaces obtained by thickening planar trees. Such groups include the braided Ptolemy-Thompson groups $T^\sharp,T^\ast$ introduced…

Group Theory · Mathematics 2022-08-17 Anthony Genevois , Anne Lonjou , Christian Urech

Hughes has defined a class of groups, which we call FSS (finite similarity structure) groups. Each FSS group acts on a compact ultrametric space by local similarities. The best-known example is Thompson's group V. Guided by previous work on…

Group Theory · Mathematics 2012-06-14 Daniel S. Farley , Bruce Hughes

We propose a new unifying framework for Thompson-like groups using a well-known device called operads and category theory as language. We discuss examples of operad groups which have appeared in the literature before. As a first…

Group Theory · Mathematics 2016-04-05 Werner Thumann

Hughes defined a class of groups that act as local similarities on compact ultrametric spaces. Guba and Sapir had previously defined braided diagram groups over semigroup presentations. The two classes of groups share some common…

Group Theory · Mathematics 2014-06-19 Daniel Farley , Bruce Hughes

We compute the higher $\Sigma$-invariants $\Sigma^m(F_{n,\infty})$ of the generalized Thompson groups $F_{n,\infty}$, for all $m,n\ge 2$. This extends the $n=2$ case done by Bieri, Geoghegan and Kochloukova, and the $m=2$ case done by…

Group Theory · Mathematics 2015-02-10 Matthew C. B. Zaremsky

We study quasimorphisms and bounded cohomology of a variety of braided versions of Thompson groups. Our first main result is that the Brin--Dehornoy braided Thompson group $bV$ has an infinite-dimensional space of quasimorphisms and thus…

Group Theory · Mathematics 2024-07-10 Francesco Fournier-Facio , Yash Lodha , Matthew C. B. Zaremsky

Bieri, Geoghegan and Kochloukova computed the BNSR-invariants $\Sigma^m(F)$ of Thompson's group $F$ for all $m$. We recompute these using entirely geometric techniques, making use of the Stein--Farley CAT(0) cube complex on which $F$ acts.

Group Theory · Mathematics 2015-04-29 Stefan Witzel , Matthew C. B. Zaremsky

We consider Thompson's groups from the perspective of mapping class groups of surfaces of infinite type. This point of view leads us to the braided Thompson groups, which are extensions of Thompson's groups by infinite (spherical) braid…

Group Theory · Mathematics 2013-10-25 Louis Funar , Christophe Kapoudjian , Vlad Sergiescu

Thompson's group F is the group of all increasing dyadic piecewise linear homeomorphisms of the closed unit interval. We compute Sigma^m(F) and Sigma^m(F;Z), the homotopical and homological Bieri-Neumann-Strebel-Renz invariants of F, and we…

Group Theory · Mathematics 2008-08-01 Robert Bieri , Ross Geoghegan , Dessislava Kochloukova

In this note, we compute the {\Sigma}^1(G) invariant when 1 {\to} H {\to} G {\to} K {\to} 1 is a short exact sequence of finitely generated groups with K finite. As an application, we construct a group F semidirect Z_2 where F is the R.…

Group Theory · Mathematics 2011-12-22 Nic Koban , Peter Wong

We describe a procedure for constructing a generalized Thompson group out of a family of groups that is equipped with what we call a cloning system. The previously known Thompson groups F, V, Vbr and Fbr arise from this procedure using,…

Group Theory · Mathematics 2018-10-25 Stefan Witzel , Matthew C. B. Zaremsky

We outline a general procedure that builds classifying spaces for generalized Thompson groups $\Gamma$. The construction depends on a small number of choices: (1) an inverse semigroup $S$ of partial transformations that ``locally determine"…

Group Theory · Mathematics 2024-09-12 Daniel Farley

We use geometric techniques to investigate several examples of quasi-isometrically embedded subgroups of Thompson's group F. Many of these are explored using the metric properties of the shift map phi in F. These subgroups have simple…

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

The braided Thompson group $\mathcal B$ is an asymptotic mapping class group of a sphere punctured along the standard Cantor set, endowed with a rigid structure. Inspired from the case of finite type surfaces we consider a Hatcher-Thurston…

Geometric Topology · Mathematics 2019-01-25 Louis Funar , Maxime Nguyen

We show that the \s{\phi}-labeled Thompson groups and the twisted Brin--Thompson groups are boundedly acyclic. This allows us to prove several new embedding results for groups. First, every group of type $F_n$ embeds quasi-isometrically…

Group Theory · Mathematics 2025-04-15 Fan Wu , Xiaolei Wu , Mengfei Zhao , Zixiang Zhou

We prove that the Brin-Thompson groups sV, also called higher dimensional Thompson's groups, are of type F_\infty for all natural numbers s. This result was previously shown for s up to 3, by considering the action of sV on a naturally…

Group Theory · Mathematics 2014-03-19 Martin Fluch , Marco Marschler , Stefan Witzel , Matthew C. B. Zaremsky

In 1984 Brown and Geoghegan proved that Thompson's group $F$ is of type $\textrm{F}_\infty$, making it the first example of an infinite dimensional torsion-free group of type $\textrm{F}_\infty$. Over the decades a different, shorter proof…

Group Theory · Mathematics 2020-06-04 Matthew C. B. Zaremsky

We describe pure braided versions of Thompson's group F. These groups, $BF$ and $\hat{BF}$, are subgroups of the braided versions of Thompson's group V, introduced by Brin and Dehornoy. Unlike V, elements of F are order-preserving self-maps…

Group Theory · Mathematics 2018-03-19 Thomas Brady , Jose Burillo , Sean Cleary , Melanie Stein
‹ Prev 1 2 3 10 Next ›