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Related papers: On Shephard Groups with Large Triangles

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We prove several results on the model theory of Artin groups, focusing on Artin groups which are ``far from right-angled Artin groups''. The first result is that if $\mathcal{C}$ is a class of Artin groups whose irreducible components are…

Logic · Mathematics 2025-07-30 Alberto Cassella , Gianluca Paolini , Giovanni Paolini

We prove that triangular configurations are plentiful in large subsets of cartesian squares of finite quasirandom groups from classes having the quasirandom ultraproduct property, for example the class of finite simple groups. This is…

Dynamical Systems · Mathematics 2018-03-13 Vitaly Bergelson , Donald Robertson , Pavel Zorin-Kranich

An odd Coxeter group $W$ is one which admits a Coxeter system $(W,S)$ for which all the exponents $m_{ij}$ are either odd or infinity. The paper investigates the family of odd Coxeter groups whose associated labeled graphs…

Group Theory · Mathematics 2021-07-19 Tushar Kanta Naik , Mahender Singh

Quantum symmetric algebras (or noncommutative polynomial rings) arise in many places in mathematics. In this article we find the multiplicative structure of their Hochschild cohomology when the coefficients are in an arbitrary bimodule…

Rings and Algebras · Mathematics 2011-05-05 Deepak Naidu , Piyush Shroff , Sarah Witherspoon

We describe an algorithm to identify a minimal set of "braid relations" which span and preserve all sets of involution words for twisted Coxeter systems of finite or affine type. We classify the cases in which adding the smallest possible…

Combinatorics · Mathematics 2017-11-22 Eric Marberg

We prove that any large even Artin group is poly-free and that any even Artin group based on a triangle graph is also poly-free.

Group Theory · Mathematics 2020-09-21 Ruben Blasco-Garcia

We study classes of right-angled Coxeter groups with respect to the strong submodel relation of parabolic subgroup. We show that the class of all right-angled Coxeter group is not smooth, and establish some general combinatorial criteria…

Logic · Mathematics 2019-12-19 Tapani Hyttinen , Gianluca Paolini

This thesis takes Brady's construction of $K(\pi,1)$s for the braid groups as a starting point. It is widely known that this construction can - with the right ingredients - be generalized to Artin groups of finite type. Results of Bessis as…

Group Theory · Mathematics 2018-10-08 Valentin Braun

We compute the two-cocycles (or multipliers) of the free nilpotent groups of class $2$ and rank $n$ and give conditions for simplicity of the corresponding twisted group $C^*$-algebras. These groups are representation groups for…

Operator Algebras · Mathematics 2016-07-08 Tron Omland

We show that a triangle Artin group $\text{Art}_{MNP}$ where $M\leq N\leq P$ splits as an amalgamated product or an HNN extension of finite rank free groups, provided that either $M>2$, or $N>3$. We also prove that all even three generator…

Group Theory · Mathematics 2021-03-03 Kasia Jankiewicz

Complex reflection groups comprise a generalization of Weyl groups of semisimple Lie algebras, and even more generally of finite Coxeter groups. They have been heavily studied since their introduction and complete classification in the…

Algebraic Geometry · Mathematics 2025-03-21 Carlos E. Arreche , Avery Bainbridge , Benjamin Obert , Alavi Ullah

Dual presentations of Coxeter groups have recently led to breakthroughs in our understanding of affine Artin groups. In particular, they led to the proof of the $K(\pi, 1)$ conjecture and to the solution of the word problem. Will the "dual…

Group Theory · Mathematics 2025-12-30 Giovanni Paolini

We investigate the planarity of the boundaries of right-angled Coxeter groups. We show that non-planarity of the defining graph does not necessarily imply non-planarity of every boundary of the associated right-angled Coxeter group,…

Geometric Topology · Mathematics 2019-02-07 Pallavi Dani , Matthew Haulmark , Genevieve Walsh

We study the second bounded cohomology of an amalgamated free product of groups, and an HNN extension of a group. As an application, we have a group with infinitely many ends has infinite dimensional second bounded cohomology.

Group Theory · Mathematics 2008-02-03 Koji Fujiwara

Braid groups are an important and flexible tool used in several areas of science, such as Knot Theory (Alexander's theorem), Mathematical Physics (Yang-Baxter's equation) and Algebraic Geometry (monodromy invariants). In this note we will…

Algebraic Geometry · Mathematics 2019-05-10 Francesco Polizzi

The superextension $\lambda(X)$ of a set $X$ consists of all maximal linked families on $X$. Any associative binary operation $*: X\times X \to X$ can be extended to an associative binary operation $*:…

Group Theory · Mathematics 2020-04-09 Taras Banakh , Volodymyr Gavrylkiv

In this paper we study the classification of right-angled Artin groups up to commensurability. We characterise the commensurability classes of RAAGs defined by trees of diameter 4. In particular, we prove a conjecture of Behrstock and…

Group Theory · Mathematics 2018-03-29 Montserrat Casals-Ruiz , Ilya Kazachkov , Alexander Zakharov

A characterization is completed for finite groups acting arc-transitively on maps with square-free Euler characteristic, associated with infinite families of regular maps of square-free Euler characteristic presented. This is based on a…

Group Theory · Mathematics 2025-12-12 P. C. Hua , C. H. Li , J. B. Zhang , H. Zhou

Groups of almost upper triangular infinite matrices with entries indexed by integers are studied. It is shown that, when the matrices are over a finite field, these groups admit a nondiscrete totally disconnected, locally compact group…

Group Theory · Mathematics 2019-12-17 Peter Groenhout , Colin D. Reid , George A. Willis

The existing algorithm to compute and verify the automata associated with an automatic group deals only with the subclass of shortlex automatic groups. This paper describes the extension of the algorithm to deal with automatic groups…

Group Theory · Mathematics 2008-02-03 Sarah Rees