English
Related papers

Related papers: Aut-invariant quasimorphisms on groups

200 papers

Let F be the free group over a set of two or more generators. R. Brooks constructed an infinite family of quasi-morphisms on F such that an infinite subfamily gives rise to independent classes in the second bounded cohomology of F, which…

Group Theory · Mathematics 2009-11-24 Pascal Rolli

We show that a large class of right-angled Artin groups (in particular, those with planar complementary defining graph) can be embedded quasi-isometrically in pure braid groups and in the group of area preserving diffeomorphisms of the disk…

Geometric Topology · Mathematics 2016-09-07 John Crisp , Bert Wiest

We build quasi--isometry invariants of relatively hyperbolic groups which detect the hyperbolic parts of the group; these are variations of the stable dimension constructions previously introduced by the authors. We prove that, given any…

Group Theory · Mathematics 2016-09-19 Matthew Cordes , David Hume

In this paper we study the hyperbolicity properties of a class of random groups arising as graph products associated to random graphs. Recall, that the construction of a graph product is a generalization of the constructions of right-angled…

Group Theory · Mathematics 2014-10-01 Ruth Charney , Michael Farber

We obtain a criterion for quasiconvexity of a subgroup of an amalgamated free product of two word hyperbolic groups along a virtually cyclic subgroup. The result provides a method of constructing new word hyperbolic group in class (Q), that…

Group Theory · Mathematics 2008-02-03 Ilya Kapovich

Last years a number of papers were devoted to describing automorphisms of semigroups of endomorphisms of free finitely generated universal algebras of some varieties: groups, semigroups, associative commutative algebras, inverse semigroups,…

General Mathematics · Mathematics 2007-05-23 Grigori Zhitomirski

We describe structure of quasihomomorphisms from arbitrary groups to discrete groups. We show that all quasihomomorphisms are 'constructible', i.e., are obtained via certain natural operations from homomorphisms to some groups and…

Group Theory · Mathematics 2015-07-09 Koji Fujiwara , Michael Kapovich

A countable graph is ultrahomogeneous if every isomorphism between finite induced subgraphs can be extended to an automorphism. Woodrow and Lachlan showed that there are essentially four types of such countably infinite graphs: the random…

Group Theory · Mathematics 2017-01-30 J. Jonušas , J. D. Mitchell

We develop a theory of \emph{strongly quasiconvex subgroups} of an arbitrary finitely generated group. Strong quasiconvexity generalizes quasiconvexity in hyperbolic groups and is preserved under quasi-isometry. We show that strongly…

Group Theory · Mathematics 2019-06-05 Hung Cong Tran

The rank of a hierarchically hyperbolic space is the maximal number of unbounded factors in a standard product region. For hierarchically hyperbolic groups, this coincides with the maximal dimension of a quasiflat. Examples for which the…

Geometric Topology · Mathematics 2020-08-25 Jason Behrstock , Mark F Hagen , Alessandro Sisto

We construct a new infinite-dimensional family of homogeneous quasimorphisms on the group of Hamiltonian diffeomorphisms of the two-sphere. Moreover, for any constant $K$ less than the total area of the sphere, we produce unbounded…

Symplectic Geometry · Mathematics 2025-12-01 Yongsheng Jia , Richard Webb

We prove that most Artin groups of large and hyperbolic type are Hopfian, meaning that every self-epimorphism is an isomorphism. The class covered by our result is generic, in the sense of Goldsborough-Vaskou. Moreover, assuming the…

Group Theory · Mathematics 2025-12-18 Giorgio Mangioni , Alessandro Sisto

We show that every graph product of finitely generated abelian groups acts properly and cocompactly on a CAT(0) cubical complex. The complex generalizes (up to subdivision) the Salvetti complex of a right-angled Artin group and the Coxeter…

Group Theory · Mathematics 2017-05-18 Kim Ruane , Stefan Witzel

We study model geometries of finitely generated groups. If a finitely generated group does not contain a non-trivial finite rank free abelian commensurated subgroup, we show any model geometry is dominated by either a symmetric space of…

Group Theory · Mathematics 2024-09-06 Alex Margolis

It is known that the canonical double cover of any connected nonbipartite graph have an automorphism group of the form $H \rtimes \mathbb{Z}_2$, where $H$ is the set of automorphism which preserve bipartite parts. We construct connected…

Combinatorics · Mathematics 2024-06-11 Bartłomiej Bychawski

We show that two-dimensional Artin groups satisfy a strengthening of the Tits alternative: their subgroups either contain a non-abelian free group or are virtually free abelian of rank at most $2$. When in addition the associated Coxeter…

Group Theory · Mathematics 2023-08-31 Alexandre Martin

We are motivated by the question that for which class of right-angled Artin groups (RAAG's), the quasi-isometry classification coincides with commensurability classification. This is previously known for RAAG's with finite outer…

Geometric Topology · Mathematics 2024-12-03 Jingyin Huang

Let G be a finitely generated relatively hyperbolic group. We show that if no peripheral subgroup of G is hyperbolic relative to a collection of proper subgroups, then the fixed subgroup of every automorphism of G is relatively quasiconvex.…

Group Theory · Mathematics 2012-11-06 Ashot Minasyan , Denis Osin

We show that if $G$ is a non-elementary word hyperbolic group, mapping class group of a hyperbolic surface or the outer automorphism group of a nonabelian free group then $G$ has $2^{\aleph_0}$ many continuous ergodic invariant random…

Group Theory · Mathematics 2015-06-02 Lewis Bowen , Rostislav Grigorchuk , Rostyslav Kravchenko

We prove that an arbitrary right-angled Artin group $G$ admits a quasi-isometric group embedding into a right-angled Artin group defined by the opposite graph of a tree. Consequently, $G$ admits quasi-isometric group embeddings into a pure…

Group Theory · Mathematics 2016-01-20 Sang-hyun Kim , Thomas Koberda