English
Related papers

Related papers: On Thompson Groups for Wa\.zewski Dendrites

200 papers

If $G$ is a finite classical group, linear or unitary in any characteristic, and orthogonal in odd characteristic, we give an approximate formula for $\chi(g)$ in which the error term is much smaller than the estimate, when $g\in G$ is an…

Group Theory · Mathematics 2025-07-18 Michael Larsen , Pham Huu Tiep

We define ``star reducible'' Coxeter groups to be those Coxeter groups for which every fully commutative element (in the sense of Stembridge) is equivalent to a product of commuting generators by a sequence of length-decreasing star…

Quantum Algebra · Mathematics 2007-05-23 R. M. Green

We consider the group $\mathfrak{X}(G)$ obtained from $G\ast G$ by forcing each element $g$ in the first free factor to commute with the copy of $g$ in the second free factor. Deceptively complicated finitely presented groups arise from…

Group Theory · Mathematics 2018-11-28 Martin R Bridson , Dessislava H Kochloukova

We study a family of groups consisting of the simplest extensions of lamplighter groups. We use these groups to answer multiple open questions in combinatorial group theory, providing groups that exhibit various combinations of properties:…

Group Theory · Mathematics 2025-07-21 Corentin Bodart

We study the notion of weak amalgamation in the context of diagonal conjugacy classes. Generalizing results of Kechris and Rosendal, we prove that for every countable structure $M$, Polish group $G$ of permutations of $M$, and $n \geq 1$,…

Logic · Mathematics 2022-03-11 Maciej Malicki

We construct the first examples of finitely presented groups where the conjugator length function is exponential; these are central extensions of groups of the form $F_m \rtimes F_2$. Further, we use a fibre product construction to exhibit…

Group Theory · Mathematics 2025-12-30 Martin R. Bridson , Timothy R. Riley

Let W be an arbitrary Coxeter group of simply-laced type (possibly infinite but of finite rank), u,v be any two elements in W, and i be a reduced word (of length m) for the pair (u,v) in the Coxeter group W\times W. We associate to i a…

Algebraic Geometry · Mathematics 2007-05-23 Boris Shapiro , Michael Shapiro , Alek Vainshtein , Andrei Zelevinsky

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

Jones introduced a method to produce unoriented links from elements of the Thompson's group $F$, and proved that any link can be produced by this construction. In this paper, we attempt to investigate the relations between conjugacy classes…

Geometric Topology · Mathematics 2025-04-03 Yuanyuan Bao , Xiaobing Sheng

In this paper we expand on previous results, studying the extent to which one can detect fusion in certain finite groups $\Gamma$, from information about the universal deformation rings of absolutely irreducible…

Rings and Algebras · Mathematics 2016-02-10 David C. Meyer

We discuss metric and combinatorial properties of Thompson's group T, including normal forms for elements and unique tree pair diagram representatives. We relate these properties to those of Thompson's group F when possible, and highlight…

Group Theory · Mathematics 2018-03-19 Jose Burillo , Sean Cleary , Melanie Stein , Jennifer Taback

We give the first examples of groups which admit a tame combing with linear radial tameness function with respect to any choice of finite presentation, but which are not minimally almost convex on a standard generating set. Namely, we…

Group Theory · Mathematics 2018-03-19 Sean Cleary , Susan Hermiller , Melanie Stein , Jennifer Taback

Let $Z\subset Fl(n)$ be the closure of a generic torus orbit in the full flag variety. Anderson-Tymoczko express the cohomology class of $Z$ as a sum of classes of Richardson varieties. Harada-Horiguchi-Masuda-Park give a decomposition of…

Algebraic Geometry · Mathematics 2024-09-04 Carl Lian

We give examples of finitely presented groups containing elements with irrational (in fact, transcendental) stable commutator length, thus answering in the negative a question of M. Gromov. Our examples come from 1-dimensional dynamics, and…

Geometric Topology · Mathematics 2007-10-02 Dongping Zhuang

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 study some combinatorial properties of the word metric of Thompson's group F in the standard two generator finite presentation. We explore connections between the tree pair diagram representing an element w of F, its normal form in the…

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

A group $G$ is invariably generated if there exists a subset $S \subseteq G$ such that, for every choice $g_s \in G$ for $s \in S$, the group $G$ is generated by $\{ s^{g_s} \mid s \in S \}$. In [GGJ16] Gelander, Golan and Juschenko showed…

Group Theory · Mathematics 2024-04-29 Davide Perego , Matteo Tarocchi

In [5], Elnitsky constructed three elegant bijections between classes of reduced words for Type $\mathrm{A}$, $\mathrm{B}$ and $\mathrm{D}$ families of Coxeter groups and certain tilings of polygons. This paper offers a particular…

Group Theory · Mathematics 2024-07-23 Robert Nicolaides , Peter Rowley

We construct new families of groups with property (T) and infinitely many alternating group quotients. One of those consists of subgroups of $\mathrm{Aut}(\mathbf F_{p}[x_1, \dots, x_n])$ generated by a suitable set of tame automorphisms.…

Group Theory · Mathematics 2023-05-29 Pierre-Emmanuel Caprace , Martin Kassabov

It is a long standing open problem whether the Thompson group $F$ is an amenable group. In this paper we show that if $A$, $B$, $C$ denote the standard generators of Thompson group $T$ and $D:=C B A^{-1}$ then…

Group Theory · Mathematics 2018-09-25 S. Haagerup , U. Haagerup , M. Ramirez-Solano