Results 11 to 20 of about 314 (23)

Thompson’s group T has quadratic Dehn function

Forum of Mathematics, Sigma
We prove that Thompson’s group T and, more generally, all the Higman–Thompson groups $T_n$ have quadratic Dehn function.
Matteo Migliorini
doaj   +1 more source

Rationality of the zeta function of the subgroups of abelian $p$-groups

, 2017
Given a finite abelian $p$-group $F$, we prove an efficient recursive formula for $\sigma_a(F)=\sum_{\substack{H\leq F}}|H|^a$ where $H$ ranges over the subgroups of $F$.
Ramaré, Olivier
core   +2 more sources

Failure of separation by quasi-homomorphisms in mapping class groups

, 2006
We show that mapping class groups of surfaces of genus at least two contain elements of infinite order that are not conjugate to their inverses, but whose powers have bounded torsion lengths. In particular every homogeneous quasi-homomorphism vanishes on
Endo, H., Kotschick, D.
core   +1 more source

The asymptotic dimension of quotients by finite groups

, 2016
Let $X$ be a proper metric space and let $F$ be a finite group acting on $X$ by isometries. We show that the asymptotic dimension of $F\backslash X$ is the same as the asymptotic dimension of $X$.Comment: 7 ...
Kasprowski, Daniel
core   +1 more source

On the subset Combinatorics of G-spaces [PDF]

, 2014
Let $G$ be a group and let $X$ be a transitive $G$-space. We classify the subsets of $X$ with respect to a translation invariant ideal $\mathcal{J}$ in the Boolean algebra of all subsets of $X$, introduce and apply the relative combinatorical derivations
Protasov, Igor, Slobodianiuk, Sergii
core   +2 more sources

Logic for metric structures and the number of universal sofic and hyperlinear groups

, 2014
Using the model theory of metric structures, I give an alternative proof of the following result by Thomas: If the Continuum Hypothesis fails then there are power of the continuum many universal sofic groups up to isomorphism.
Lupini, Martino
core   +1 more source

Isometric group actions on Hilbert spaces: structure of orbits

, 2006
Our main result is that a finitely generated nilpotent group has no isometric action on an infinite-dimensional Hilbert space with dense orbits. In contrast, we construct such an action with a finitely generated metabelian group.Comment: 12 pages, to ...
Alain Valette, Guichardet, Guichardet, Martin, Romain Tessera, Yves de Cornulier   +5 more
core   +1 more source

Class-preserving automorphisms of universal hyperlinear groups [PDF]

, 2013
We show that the group of class-preserving automorphisms of a universal hyperlinear group has index 2 inside the group of all automorphisms.Comment: 4 ...
Lupini, Martino
core  

Law of large numbers for the drift of the two-dimensional wreath product. [PDF]

Probab Theory Relat Fields, 2022
Erschler A, Zheng T.
europepmc   +1 more source

Number of Directions Determined by a Set in F q 2 and Growth in Aff ( F q ). [PDF]

Discrete Comput Geom, 2021
Dona D.
europepmc   +1 more source