English
Related papers

Related papers: On identities in Thompson's group

200 papers

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 prove that Thompson's group $V$ is acyclic, answering a 1992 question of Brown in the positive. More generally, we identify the homology of the Higman-Thompson groups $V_{n,r}$ with the homology of the zeroth component of the infinite…

Group Theory · Mathematics 2019-05-24 Markus Szymik , Nathalie Wahl

We show that the fundamental group is not invariant under derived equivalence of smooth projective varieties.

Algebraic Geometry · Mathematics 2011-12-16 Christian Schnell

We show that the de Jong fundamental group of any non-trivial abelian variety over a complete algebraically closed extension $C/\mathbb{Q}_p$ is non-abelian. Generalizing an argument for $\mathbb{P}^1_C$, we also show that the de Jong…

Algebraic Geometry · Mathematics 2025-12-19 Sean Howe

We revisit our construction of the Thompson groups from the polycyclic inverse monoids in the light of new research. Specifically, we prove that the Thompson group $G_{n,1}$ is the group of units of a Boolean inverse monoid $C_{n}$ called…

Group Theory · Mathematics 2020-06-30 Mark V Lawson

We show that labelled Thompson groups and twisted Brin--Thompson groups are all acyclic. This allows us to prove several new embedding results for groups. First, every group of type $F_n$ embeds quasi-isometrically as a subgroup of an…

Group Theory · Mathematics 2025-10-21 Martin Palmer , Xiaolei Wu

We construct a "higher dimensional" version 2V of Thompson's group V. Like V it is an infinite, finitely presented, simple subgroup of the homeomorphism group of the Cantor set, but we show that it is not isomorphic to V by showing that the…

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

We show that R. Thompson's group $T$ is a maximal subgroup of the group $V$. The argument provides examples of foundational calculations which arise when expressing elements of $V$ as products of transpositions of basic clopen sets in…

Group Theory · Mathematics 2025-04-21 James Belk , Collin Bleak , Martyn Quick , Rachel Skipper

A proof of Thompson's conjecture for real semi-simple Lie groups has been given by Kapovich, Millson, and Leeb. In this note, we give another proof of the conjecture by using a theorem of Alekseev, Meinrenken, and Woodward from symplectic…

Symplectic Geometry · Mathematics 2007-05-23 Jiang-Hua Lu , Sam Evens

In a seminal paper, Brin demonstrates that the outerautomorphism group of Thompson group $T$ is isomorphic to the cyclic group of order two. In this article, building on characterisation of automorphisms of the Higman-Thompson groups…

Group Theory · Mathematics 2020-04-01 Feyishayo Olukoya

Let $\mu$ be a nondegenerate probability measure with finite entropy on a countable group $G \leq \mathrm{Homeo}_+(S^1)$ of orientation-preserving homeomorphisms of the circle acting proximally, minimally and topologically nonfreely on…

Dynamical Systems · Mathematics 2025-04-03 Martín Gilabert Vio , Cosmas Kravaris , Eduardo Silva

Every finite simple group can be generated by two elements and, in fact, every nontrivial element is contained in a generating pair. Groups with this property are said to be $\frac{3}{2}$-generated, and the finite $\frac{3}{2}$-generated…

Group Theory · Mathematics 2023-07-14 Collin Bleak , Scott Harper , Rachel Skipper

We prove that a limit group over Thompson's group $F$ cannot be an HNN-extension of $F$ with respect to a finitely generated subgroup. On the other hand we give an example of an $F$-limit group which is a centralized HNN-extenstions of $F$.…

Group Theory · Mathematics 2025-09-25 Aleksander Ivanov , Roland Zarzycki

We prove that the links associated with positive elements of the oriented subgroup of the Thompson group are positive.

Geometric Topology · Mathematics 2025-01-13 Valeriano Aiello , Sebastian Baader

We show that the Diophantine problem in Thompson's group F is undecidable. Our proof uses the facts that F has finite commutator width and rank 2 abelianisation, then uses similar arguments used by B\"uchi and Senger and Ciobanu and Garreta…

Group Theory · Mathematics 2025-04-21 Luna Elliott , Alex Levine

Let W be a Weyl group. In my 1984 book a group was attached to any special representation of W using the theory of Springer representations. In this paper we give a new definition of this group which is purely algebraic (no use of geometry…

Representation Theory · Mathematics 2025-05-02 G. Lusztig

We show that the quantum disk, i.e. the quantum space corresponding to the Toeplitz C*-algebra does not admit any compact quantum group structure. We prove that if such a structure existed the resulting compact quantum group would…

Operator Algebras · Mathematics 2020-05-07 Jacek Krajczok , Piotr M. Sołtan

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

Given any linear isometry from a Hilbert space to its square one can explicitly construct a so-called Pythagorean unitary representation of Richard Thompson's group F. We introduce a condition on the isometry implying that the associated…

Group Theory · Mathematics 2022-11-17 Arnaud Brothier , Dilshan Wijesena

We prove that Richard Thompson's group F is not minimally almost convex with respect to the two standard generators. This improves upon a recent result of S. Cleary and J. Taback. We make use of the forest diagrams for elements of F…

Group Theory · Mathematics 2007-05-23 James Belk , Kai-Uwe Bux