activity
20112026
most citedHierarchically hyperbolic spaces I: curve complexes for cubical groups

149 citations · 710 across the 38 of their papers we have counts for

collaborators

39 papers

math.GR2026

Periodic quasiflats in hierarchically hyperbolic spaces

Pénélope Azuelos, Mark Hagen

We prove a quasiflat closing theorem and a coarse flat torus theorem for hierarchically hyperbolic groups (HHGs). Namely, given an HHG , we prove that is hyperbolic if and o…

math.GT2026

Coarse embeddings of products of trees as quasi-isometry invariants

Mark Hagen, Alessandro Sisto

We consider the maximal number of factors of a product of bushy trees that can be quasi-isometrically, or even coarsely embedded into various groups of interest, including mapping…

math.GR2025

Characterizing hierarchically hyperbolic free by cyclic groups

Eliot Bongiovanni, Pritam Ghosh, Funda Gültepe +1

We algebraically characterize free by cyclic groups that have coarse medians, and prove that this is equivalent to the a priori stronger properties of being colourable hierarchical…

math.GR2025

Combination theorems for Wise's power alternative

Mark Hagen, Alexandre Martin, Giovanni Sartori

We show that Wise's power alternative is stable under certain group constructions, use this to prove the power alternative for new classes of groups, and recover known results from…

math.GR2023

Induced quasi-isometries of hyperbolic spaces, Markov chains, and acylindrical hyperbolicity

Antoine Goldsborough, Mark Hagen, Harry Petyt +2

We show that quasi-isometries of (well-behaved) hierarchically hyperbolic groups descend to quasi-isometries of their maximal hyperbolic space. This has two applications, one relat…

math.GR2023

A Combinatorial Structure for Many Hierarchically Hyperbolic Spaces

Mark Hagen, Giorgio Mangioni, Alessandro Sisto

The combinatorial hierarchical hyperbolicity criterion is a very useful way of constructing new hierarchically hyperbolic spaces (HHSs). We show that, conversely, HHSs satisfying n…

math.GT2023

Uniform undistortion from barycentres, and applications to hierarchically hyperbolic groups

Carolyn Abbott, Mark Hagen, Harry Petyt +1

We show that infinite cyclic subgroups of groups acting uniformly properly on injective metric spaces are uniformly undistorted. In the special case of hierarchically hyperbolic gr…

math.GT2023★ 2 cited

Homotopy equivalent boundaries of cube complexes

Talia Fernós, David Futer, Mark Hagen

A finite-dimensional CAT(0) cube complex is equipped with several well-studied boundaries. These include the Tits boundary (which depends on the CAT(0) metric), the Roller boun…

math.GT2022★ 2 cited

Equivariant hierarchically hyperbolic structures for 3-manifold groups via quasimorphisms

Mark Hagen, Jacob Russell, Alessandro Sisto +1

Behrstock, Hagen, and Sisto classified 3-manifold groups admitting a hierarchically hyperbolic space structure. However, these structures were not always equivariant with respect t…

math.GR2022

Some examples of separable convex-cocompact subgroups

Mark Hagen, Alessandro Sisto

Reid asked whether all convex-cocompact subgroups of mapping class groups are separable. Using a construction of Manning-Mj-Sageev, we give examples of separable convex-cocompact s…

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

Projection complexes and quasimedian maps

Mark Hagen, Harry Petyt

We use the projection complex machinery of Bestvina--Bromberg--Fujiwara to study hierarchically hyperbolic groups. In particular, we show that if the group has a BBF colouring and…

math.GR2020★ 8 cited

Large facing tuples and a strengthened sector lemma

Mark Hagen

We prove a strengthened sector lemma for irreducible, finite-dimensional, locally finite, essential, cocompact CAT(0) cube complexes under the additional hypothesis that the comple…

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.GT2019★ 4 cited

Deforming cubulations of hyperbolic groups

Elia Fioravanti, Mark Hagen

We describe a procedure to deform cubulations of hyperbolic groups by "bending hyperplanes". Our construction is inspired by related constructions like Thurston's Mickey Mouse exam…

math.GR2019★ 11 cited

A remark on thickness of free-by-cyclic groups

Mark Hagen

Let be a free group of positive, finite rank and let be a polynomial-growth automorphism. Then is strongly thick of order , where is…

math.GR2018★ 9 cited

Dehn filling Dehn twists

François Dahmani, Mark Hagen, Alessandro Sisto

Let be the genus-- oriented surface with punctures, with either or . We show that is acylindrically hyperbolic where is the norma…

math.GR2017★ 10 cited

Panel collapse and its applications

Mark F. Hagen, Nicholas W. M. Touikan

We describe a procedure called panel collapse for replacing a CAT(0) cube complex by a "lower complexity" CAT(0) cube complex whenever contains a codimension-$2…

math.GT2017

Quasiflats in hierarchically hyperbolic spaces

Jason Behrstock, Mark F Hagen, Alessandro Sisto

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…

math.GR2016★ 39 cited

On hierarchical hyperbolicity of cubical groups

Mark F Hagen, Tim Susse

Let X be a proper CAT(0) cube complex admitting a proper cocompact action by a group G. We give three conditions on the action, any one of which ensures that X has a factor system…

cs.CL2016★ 24 cited

Meta-Evaluation of Translation Evaluation Methods: a systematic up-to-date overview

Lifeng Han, Serge Gladkoff

Starting from the 1950s, Machine Translation (MT) was challenged by different scientific solutions, which included rule-based methods, example-based and statistical models (SMT), t…

math.GT2016★ 56 cited

Boundaries and automorphisms of hierarchically hyperbolic spaces

Matthew G. Durham, Mark F. Hagen, Alessandro Sisto

Hierarchically hyperbolic spaces provide a common framework for studying mapping class groups of finite type surfaces, Teichmüller space, right-angled Artin groups, and many other…

math.GR2016★ 1 cited

Acylindrical hyperbolicity of cubical small-cancellation groups

Goulnara N. Arzhantseva, Mark F. Hagen

We provide an analogue of Strebel's classification of geodesic triangles in classical groups for groups given by Wise's cubical presentations satisfying sufficiently…

math.GR2015★ 29 cited

Asymptotic dimension and small-cancellation for hierarchically hyperbolic spaces and groups

Jason Behrstock, Mark F. Hagen, Alessandro Sisto

We prove that all hierarchically hyperbolic spaces have finite asymptotic dimension and obtain strong bounds on these dimensions. One application of this result is to obtain the sh…