English
Related papers

Related papers: Thompson's Group F is Not Kahler

200 papers

Let $G$ be a non-amenable locally compact group and $K$ a compact subgroup of $G$ such that $(G,K)$ is a Gelfand pair. We show that if $G$ admits a suitable boundary representation which is topologically irreducible and not unitarizable,…

Functional Analysis · Mathematics 2026-02-25 Max Carter , Jared T. White

We prove a theorem of Tits type about automorphism groups for compact Kahler manifolds, which has been conjectured in the paper [KOZ].

Dynamical Systems · Mathematics 2018-09-24 De-Qi Zhang

We proved a conjecture of D. Freed that there are no non-trivial complete special Kaehler manifolds.

Differential Geometry · Mathematics 2007-05-23 Zhiqin Lu

We give a construction for twisted equivariant K-theory in the case of a proper action of a discrete group using twisted bundles. Our construction uses results of Lueck and Oliver to extend a construction of Adem and Ruan. We also show the…

K-Theory and Homology · Mathematics 2007-10-12 Christopher Dwyer

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 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

The groups G_{k,1} of Richard Thompson and Graham Higman can be generalized in a natural way to monoids, that we call M_{k,1}, and to inverse monoids, called Inv_{k,1}; this is done by simply generalizing bijections to partial functions or…

Group Theory · Mathematics 2016-01-27 J. C. Birget

The main purpose of this paper is to prove a group-theoretic generalization of a theorem of Katz on isocrystals. Along the way we reprove the group-theoretic generalization of Mazur's inequality for isocrystals due to Rapoport-Richartz, and…

Representation Theory · Mathematics 2007-05-23 Robert E. Kottwitz

The aim of this note is to show that weak relative hyperbolicity of a group relative to a subgroup (or relative hyperbolicity in the sense of Farb) does not imply any natural analogues of some well-known algebraic properties of ordinary…

Group Theory · Mathematics 2007-05-23 D. V. Osin

We show that the canonical actions of the Thompson group V and its generalizations on the Cantor set are not strongly ergodic. This implies that the associated crossed product von Neumann algebras are not full. This also yields a…

Dynamical Systems · Mathematics 2025-10-16 Ryoya Arimoto

We prove that Claas R\"over's Thompson-Grigorchuk simple group $V\mathcal{G}$ has type $F_\infty$. The proof involves constructing two complexes on which $V\mathcal{G}$ acts: a simplicial complex analogous to the Stein complex for $V$, and…

Group Theory · Mathematics 2014-11-18 James Belk , Francesco Matucci

We establish certain "non-triviality" results for several filtrations of the smooth and topological knot concordance groups. First, as regards the n-solvable filtration of the topological knot concordance group defined by K. Orr, P.…

Geometric Topology · Mathematics 2008-03-22 Tim D. Cochran , Taehee Kim

Given a Kaehler group $G$ and a primitive class $\phi \in H^1(G;Z)$, we show that the rank gradient of $(G;\phi)$ is zero if and only if Ker $\phi$ is finitely generated. Using this approach, we give a quick proof of the fact (originally…

Geometric Topology · Mathematics 2018-12-24 Stefan Friedl , Stefano Vidussi

We study subgroups $H_U$ of the R. Thompson group $F$ which are stabilizers of finite sets $U$ of numbers in the interval $(0,1)$. We describe the algebraic structure of $H_U$ and prove that the stabilizer $H_U$ is finitely generated if and…

Group Theory · Mathematics 2016-07-05 Gili Golan , Mark Sapir

We present an example of two isotopic but not strongly isotopic commutative semifields. This example shows that a recent result of Coulter and Henderson on semifield of order p^n, n odd, can not be generalized to the case n even.

Combinatorics · Mathematics 2012-03-08 Yue Zhou

We consider generalisations of Thompson's group $V$, denoted by $V_r(\Sigma)$, which also include the groups of Higman, Stein and Brin. It was shown by the authors in [20] that under some mild conditions these groups and centralisers of…

Group Theory · Mathematics 2018-07-25 Conchita Martínez-Pérez , Francesco Matucci , Brita E. A. Nucinkis

We construct a finitely presented group with coNP-complete word problem, and a finitely generated simple group with coNP-complete word problem. These groups are represented as Thompson groups, hence as partial transformation groups of…

Group Theory · Mathematics 2007-05-23 Jean-Camille Birget

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

The purpose of this article is to formulate conjectural generalizations of Hindman's Theorem and Ellis's Lemma for nonassociative binary systems and relate them to the amenability problem for Thompson's group $F$. Partial results are…

Combinatorics · Mathematics 2018-07-18 Justin Tatch Moore

We construct families of non-trivial universal rigid secondary classes for foliations, and then discuss their application to prove that foliations are not homotopic. An observation of Lawson about the non-triviality of the normal Pontrjagin…

Algebraic Topology · Mathematics 2024-03-15 Steven Hurder