[HTML][HTML] Helly meets Garside and Artin

J Huang, D Osajda - Inventiones mathematicae, 2021 - Springer
A graph is Helly if every family of pairwise intersecting combinatorial balls has a nonempty
intersection. We show that weak Garside groups of finite type and FC-type Artin groups are …

[图书][B] Weakly modular graphs and nonpositive curvature

J Chalopin, V Chepoi, H Hirai, D Osajda - 2020 - ams.org
This article investigates structural, geometrical, and topological characterizations and
properties of weakly modular graphs and of cell complexes derived from them. The unifying …

Lattices, injective metrics and the conjecture

T Haettel - arXiv preprint arXiv:2109.07891, 2021 - arxiv.org
Starting with a lattice with an action of $\mathbb {Z} $ or $\mathbb {R} $, we build a Helly
graph or an injective metric space. We deduce that the $\ell^\infty $ orthoscheme complex of …

Computing the nc-rank via discrete convex optimization on CAT (0) spaces

M Hamada, H Hirai - SIAM Journal on Applied Algebra and Geometry, 2021 - SIAM
We study the noncommutative rank (nc-rank) computation of a symbolic matrix whose
entries are linear forms in noncommutative variables. For this problem, polynomial time …

Artin groups of infinite type: trivial centers and acylindrical hyperbolicity

R Charney, R Morris-Wright - Proceedings of the American Mathematical …, 2019 - ams.org
While finite type Artin groups and right-angled Artin groups are well understood, little is
known about more general Artin groups. In this paper we use the action of an infinite type …

A link condition for simplicial complexes, and CUB spaces

T Haettel - arXiv preprint arXiv:2211.07857, 2022 - arxiv.org
We motivate the study of metric spaces with a unique convex geodesic bicombing, which we
call CUB spaces. These encompass many classical notions of nonpositive curvature, such …

Old and new challenges in Hadamard spaces

M Bacák - arXiv preprint arXiv:1807.01355, 2018 - arxiv.org
Hadamard spaces have traditionally played important roles in geometry and geometric
group theory. More recently, they have additionally turned out to be a suitable framework for …

Acylindrical actions for two-dimensional Artin groups of hyperbolic type

A Martin, P Przytycki - International Mathematics Research …, 2022 - academic.oup.com
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 subcomplexes of its …

Large‐type Artin groups are systolic

J Huang, D Osajda - Proceedings of the London Mathematical …, 2020 - Wiley Online Library
We prove that Artin groups from a class containing all large‐type Artin groups are systolic.
This provides a concise yet precise description of their geometry. Immediate consequences …

Virtually cocompactly cubulated Artin–Tits groups

T Haettel - International Mathematics Research Notices, 2021 - academic.oup.com
We give a conjectural classification of virtually cocompactly cubulated Artin–Tits groups (ie,
having a finite index subgroup acting geometrically on a CAT (0) cube complex), which we …