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20122026
most citedComplexes of Groups and Boundaries

24 citations · 111 across the 23 of their papers we have counts for

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math.GR2026

A Deligne complex for virtual Artin groups

Federica Gavazzi, Alexandre Martin

Virtual Artin groups were recently introduced by Bellingeri-Paris-Thiel as a generalisation of virtual braid groups. In this article, we initiate a geometric study of these groups…

math.GR2024

Homomorphisms between XL-type Artin groups

Martín Blufstein, Alexandre Martin, Nicolas Vaskou

We study homomorphisms between XL-type Artin groups and show that, in a suitable sense, a generic Artin group is both hopfian and co-hopfian. For XL-type Artin groups over complete…

math.GR2024

Acylindrical hyperbolicity for Artin groups with a visual splitting

Ruth Charney, Alexandre Martin, Rose Morris-Wright

We establish a criterion that implies the acylindrical hyperbolicity of many Artin groups admitting a visual splitting. This gives a variety of new examples of acylindrically hyper…

math.GR2023

Characterising large-type Artin groups

Alexandre Martin, Nicolas Vaskou

We show that the class of large-type Artin groups is invariant under isomorphism, in stark contrast with the corresponding situation for Coxeter groups. We obtain this result by pr…

math.GR2022

The Tits Alternative for two-dimensional Artin groups and Wise's Power Alternative

Alexandre Martin

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…

math.GR2021

Extra-large type Artin groups are hierarchically hyperbolic

Mark Hagen, Alexandre Martin, Alessandro Sisto

We show that Artin groups of extra-large type, and more generally Artin groups of large and hyperbolic type, are hierarchically hyperbolic. This implies in particular that these gr…

math.GR2021★ 1 cited

Parabolic subgroups of large-type Artin groups

María Cumplido, Alexandre Martin, Nicolas Vaskou

We show that the geometric realisation of the poset of proper parabolic subgroups of a large-type Artin group has a systolic geometry. We use this geometry to show that the set of…

math.GR2020★ 2 cited

Abelian subgroups of two-dimensional Artin groups

Alexandre Martin, Piotr Przytycki

We classify abelian subgroups of two-dimensional Artin groups.

math.GR2020★ 13 cited

A combinatorial take on hierarchical hyperbolicity and applications to quotients of mapping class groups

Jason Behrstock, Mark Hagen, Alexandre Martin +1

We give a simple combinatorial criterion, in terms of an action on a hyperbolic simplicial complex, for a group to be hierarchically hyperbolic. We apply this to show that quotient…

math.GR2019

Tits alternative for Artin groups of type FC

Alexandre Martin, Piotr Przytycki

Given a group action on a finite-dimensional CAT(0) cube complex, we give a simple criterion phrased purely in terms of cube stabilisers that ensures that the group satisfies the s…

math.GR2019

Acylindrical actions for two-dimensional Artin groups of hyperbolic type

Alexandre Martin, Piotr Przytycki

For a two-dimensional Artin group whose associated Coxeter group is hyperbolic, we prove that the action of on the hyperbolic space obtained by coning off certain subcomple…

math.GR2018★ 24 cited

Automorphisms of graph products of groups from a geometric perspective

Anthony Genevois, Alexandre Martin

This article studies automorphism groups of graph products of arbitrary groups. We completely characterise automorphisms that preserve the set of conjugacy classes of vertex groups…

math.GR2018

A combination theorem for combinatorially non-positively curved complexes of hyperbolic groups

Alexandre Martin, Damian Osajda

We prove a combination theorem for hyperbolic groups, in the case of groups acting on complexes displaying combinatorial features reminiscent of non-positive curvature. Such comple…

math.GR2018★ 1 cited

Automorphism groups of cyclic products of groups

Anthony Genevois, Alexandre Martin

This article initiates a geometric study of the automorphism groups of general graph products of groups, and investigates the algebraic and geometric structure of automorphism grou…

math.GR2016

A note on the acylindrical hyperbolicity of groups acting on CAT(0) cube complexes

Indira Chatterji, Alexandre Martin

We study the acylindrical hyperbolicity of groups acting by isometries on CAT(0) cube complexes, and obtain simple criteria formulated in terms of stabilisers for the action. Namel…

math.GR2016★ 20 cited

Quasi-isometries Between Groups with Two-Ended Splittings

Christopher H. Cashen, Alexandre Martin

We construct `structure invariants' of a one-ended, finitely presented group that describe the way in which the factors of its JSJ decomposition over two-ended subgroups fit togeth…

math.GR2015★ 5 cited

On the acylindrical hyperbolicity of the tame automorphism group of

Alexandre Martin

We introduce the notion of über-contracting element, a strengthening of the notion of strongly contracting element which yields a particularly tractable criterion to show the acyli…

math.GR2015

Acylindrical actions on CAT(0) square complexes

Alexandre Martin

For group actions on hyperbolic CAT(0) square complexes, we show that the acylindricity of the action is equivalent to a weaker form of acylindricity phrased purely in terms of sta…

math.GR2015★ 8 cited

On the cubical geometry of Higman's group

Alexandre Martin

We investigate the cocompact action of Higman's group on a CAT(0) square complex associated to its standard presentation. We show that this action is in a sense intrinsic, which al…

math.GR2014

A combination theorem for cubulation in small cancellation theory over free products

Alexandre Martin, Markus Steenbock

We prove that a group obtained as a quotient of the free product of finitely many cubulable groups by a finite set of relators satisfying the classical --small cancellatio…

math.GR2014★ 6 cited

Finite index subgroups without unique product in graphical small cancellation groups

Dominik Gruber, Alexandre Martin, Markus Steenbock

We construct torsion-free hyperbolic groups without unique product whose subgroups up to some given finite index are themselves non-unique product groups. This is achieved by gener…

math.GR2013

Combination of classifying spaces for proper actions

Alexandre Martin

Given a group action on a simplicial complex such that each simplex stabiliser admits a cocompact model of classifying space for proper actions, we give conditions implying the exi…

math.GR2013

Complexes of groups and geometric small cancellation over graphs of groups

Alexandre Martin

We explain and generalise a construction due to Gromov to realise geometric small cancellation groups over graphs of groups as fundamental groups of non-positively curved 2-dimensi…