Results 41 to 50 of about 1,418 (58)

Tree-like graphings, wallings, and median graphings of equivalence relations

Forum of Mathematics, Sigma
We prove several results showing that every locally finite Borel graph whose large-scale geometry is ‘tree-like’ induces a treeable equivalence relation.
Ruiyuan Chen, Antoine Poulin, Ran Tao, Anush Tserunyan   +3 more
doaj   +1 more source

Bounded characteristic classes and flat bundles

, 2012
Let G be a connected Lie group, G^d the underlying discrete group, and BG, BG^d their classifying spaces. Let R denote the radical of G. We show that all classes in the image of the canonical map in cohomology H^*(BG,R)->H^*(BG^d,R) are bounded if and ...
Chatterji, Indira, Cornulier, Yves, Mislin, Guido, Pittet, Christophe   +3 more
core   +4 more sources

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

Limit trees for free group automorphisms: universality

Forum of Mathematics, Sigma
To any free group automorphism, we associate a universal (cone of) limit tree(s) with three defining properties: first, the tree has a minimal isometric action of the free group with trivial arc stabilizers; second, there is a unique expanding dilation ...
Jean Pierre Mutanguha
doaj   +1 more source

Posets arising from decompositions of objects in a monoidal category

Forum of Mathematics, Sigma
Given a symmetric monoidal category ${\mathcal C}$ with product $\sqcup $ , where the neutral element for the product is an initial object, we consider the poset of $\sqcup $ -complemented subobjects of a given object X.
Kevin Ivan Piterman, Volkmar Welker
doaj   +1 more source

Group Approximation in Cayley Topology and Coarse Geometry, Part II: Fibred Coarse Embeddings

Analysis and Geometry in Metric Spaces, 2019
The objective of this series is to study metric geometric properties of disjoint unions of Cayley graphs of amenable groups by group properties of the Cayley accumulation points in the space of marked groups.
Mimura Masato, Sako Hiroki
doaj   +1 more source

The conjugacy problem for $\operatorname {Out}(F_3)$

Forum of Mathematics, Sigma
We present a solution to the conjugacy problem in the group of outer automorphisms of $F_3$ , a free group of rank 3. We distinguish according to several computable invariants, such as irreducibility, subgroups of polynomial growth and subgroups ...
François Dahmani, Stefano Francaviglia, Armando Martino, Nicholas Touikan   +3 more
doaj   +1 more source

Uniformly exponential growth and mapping class groups of surfaces

, 2005
We show that the mapping class group of an orientable finite type surface has uniformly exponential growth, as well as various closely related groups.
Anderson, James W., Aramayona, Javier, Shackleton, Kenneth J.   +2 more
core   +1 more source

Extension of Paul Erdős graph on hypergroups

Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica
This paper introduces ultra non-commutative graphs derived from ultra non-commutative hypergroups. Vertices represent ultra non -commutative elements of the hypergroup U, defined as AU = {x ∈ U |Ǝy ∈ U, y ○ x ∩ x ○ y = ∅}. An edge connects vertices x and
Shamsadini S., Aghabozorgi H., Jafarpour M., Hoskova-Mayerova S.   +3 more
doaj   +1 more source

Lattices in a product of trees, hierarchically hyperbolic groups and virtual torsion-freeness. [PDF]

Bull Lond Math Soc, 2022
Hughes S.
europepmc   +1 more source