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Related papers: Thompson's quandle

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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

We prove that Thompson's group $F$ has a subgroup $H$ such that the conjugacy problem in $H$ is undecidable and the membership problem in $H$ is easily decidable. The subgroup $H$ of $F$ is a closed subgroup of $F$. That is, every function…

Group Theory · Mathematics 2021-05-04 Gili Golan , Mark Sapir

This is a survey of our recent results on the amenability problem for Thompson's group $F$. They mostly concern esimating the density of finite subgraphs in Cayley graphs of $F$ for various systems of generators, and also equations in the…

Group Theory · Mathematics 2024-02-14 Victor Guba

We study centralisers of finite order automorphisms of generalisations of Thompson's group F and conjugacy classes of finite subgroups in finite extensions of these groups. In particular, we show that centralisers of finite automorphisms in…

Group Theory · Mathematics 2010-02-10 D. H. Kochloukova , C. Martínez-Pérez , B. E. A. Nucinkis

We show that each of Thompson's groups F, T, and V have infinitely many ends relative to certain subgroups. We go on to show that T and V both have Serre's property FA, i.e., any action of T or V on a tree will have a fixed point. (The…

Group Theory · Mathematics 2007-08-13 Daniel Farley

The authors classify the finite index subgroups of R. Thompson's group $F$. All such groups that are not isomorphic to $F$ are non-split extensions of finite cyclic groups by $F$. The classification describes precisely which finite index…

Group Theory · Mathematics 2007-11-08 Collin Bleak , Bronlyn Wassink

We solve the twisted conjugacy problem on Thompson's group F. We also exhibit orbit undecidable subgroups of Aut(F), and give a proof that Aut(F) and Aut_+(F) are orbit decidable provided a certain conjecture on Thompson's group T is true.…

Group Theory · Mathematics 2013-09-10 José Burillo , Francesco Matucci , Enric Ventura

We prove that Thompson's group $T$ and, more generally, all the Higman-Thompson groups $T_n$ have quadratic Dehn function.

Group Theory · Mathematics 2025-07-11 Matteo Migliorini

In this paper it is proved that the pure braided Thompson's group BF admits a bi-order, analog to the bi-order of the pure braid groups.

Group Theory · Mathematics 2007-05-23 Jose Burillo , Juan Gonzalez-Meneses

We determine the abstract commensurator com(F) of Thompson's group F and describe it in terms of piecewise linear homeomorphisms of the real line and in terms of tree pair diagrams. We show com (F) is not finitely generated and determine…

Group Theory · Mathematics 2014-11-11 José Burillo , Sean Cleary , Claas E. Röver

In this paper we prove that the general version, F(N) of the Thompson group is inner amenable. As a consequence we generalize a result of P.Jolissaint. To do so, we prove first that F(N) together with a normal subgroup are i.c.c (infinite…

Operator Algebras · Mathematics 2007-05-23 Gabriel Picioroaga

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 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

We prove that a subquandle of a free quandle is free.

Group Theory · Mathematics 2019-04-16 Sergei O. Ivanov , Georgii Kadantsev , Kirill Kuznetsov

We show that Thompson's group $F$ has a topological action on a compact metric space that is proximal and has no fixed points.

Group Theory · Mathematics 2020-05-14 Yair Hartman , Kate Juschenko , Omer Tamuz , Pooya Vahidi Ferdowsi

We show that Thompson's group F is the symmetry group of the "generic idempotent". That is, take the monoidal category freely generated by an object A and an isomorphism A \otimes A --> A; then F is the group of automorphisms of A.

Group Theory · Mathematics 2010-03-15 Marcelo Fiore , Tom Leinster

We prove that certain Fuchsian triangle groups are profinitely rigid in the absolute sense, i.e. each is distinguished from all other finitely generated, residually finite groups by its set of finite quotients. We also develop a method…

Group Theory · Mathematics 2021-10-04 M. R. Bridson , D. B. McReynolds , A. W. Reid , R. Spitler

We obtain a characterisation of confined subgroups of Thompson's group $F$. As a result, we deduce that orbital graph of a point under action of $F$ has uniformly subexponential growth if and only if this point is fixed by the commutator…

Group Theory · Mathematics 2018-10-08 Maksym Chaudkhari

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

Pursueing our investigations on the relations between Thompson groups and mapping class groups, we introduce the group $T^*$ (and its further generalizations) which is an extension of the Ptolemy-Thompson group $T$ by means of the full…

Geometric Topology · Mathematics 2014-11-11 Louis Funar , Christophe Kapoudjian