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Related papers: Reflection length in non-affine Coxeter groups

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We extend a result of Lewis and Reiner from finite Coxeter groups to all Coxeter groups by showing that two reflection factorizations of a Coxeter element lie in the same Hurwitz orbit if and only if they share the same multiset of…

Combinatorics · Mathematics 2019-01-18 Patrick Wegener , Sophiane Yahiatene

In this article we give a simple, almost uniform proof that the lattice of noncrossing partitions associated with a well-generated complex reflection group is lexicographically shellable. So far a uniform proof is available only for Coxeter…

Combinatorics · Mathematics 2015-07-03 Henri Mühle

Let $W$ be a finite Coxeter group. We classify the reflection subgroups of $W$ up to conjugacy and give necessary and sufficient conditions for the map that assigns to a reflection subgroup $R$ of $W$ the conjugacy class of its Coxeter…

Group Theory · Mathematics 2012-01-26 J. Matthew Douglass , Goetz Pfeiffer , Gerhard Roehrle

We study the set G of growth rates of of ideal Coxeter groups in hyperbolic 3-space which consists of real algebraic integers greater than 1. We show that (1) G is unbounded above while it has the minimum, (2) any element of G is a Perron…

Geometric Topology · Mathematics 2015-07-10 Yohei Komori , Tomoshige Yukita

The depth statistic was defined by Petersen and Tenner for an element of an arbitrary Coxeter group in terms of factorizations of the element into a product of reflections. It can also be defined as the minimal cost, given certain…

Combinatorics · Mathematics 2017-01-13 Eli Bagno , Riccardo Biagioli , Mordechai Novick , Alexander Woo

A hyperbolic 3-simplex reflection group is a Coxeter group arising as a lattice in the isometry group of hyperbolic 3-space, with fundamental domain a geodesic simplex (possibly with some ideal vertices). The classification of these groups…

K-Theory and Homology · Mathematics 2009-04-13 J. -F. Lafont , I. J. Ortiz

Let $W$ be an extended affine Weyl group. We prove that minimal length elements $w_{\co}$ of any conjugacy class $\co$ of $W$ satisfy some special properties, generalizing results of Geck and Pfeiffer \cite{GP} on finite Weyl groups. We…

Representation Theory · Mathematics 2019-02-20 Xuhua He , Sian Nie

H.S.M. Coxeter showed that a group $\Gamma$ is a finite reflection group of an Euclidean space if and only if $\Gamma$ is a finite Coxeter group. In this paper, we define {\it reflections} of geodesic spaces in general, and we prove that…

Group Theory · Mathematics 2007-05-23 Tetsuya Hosaka

Let $W$ be a Coxeter group and $r\in W$ a reflection. If the group of order 2 generated by $r$ is the intersection of all the maximal finite subgroups of $W$ that contain it, then any isomorphism from $W$ to a Coxeter group $W'$ must take…

Group Theory · Mathematics 2007-05-23 W. N. Franzsen , R. B. Howlett , B. Mühlherr

We determine the maximal hyperbolic reflection groups associated to the quadratic forms $-3x_0^2 + x_1^2 + ... + x_n^2$, $n \ge 2$, and present the Coxeter schemes of their fundamental polyhedra. These groups exist in dimensions up to 13,…

Group Theory · Mathematics 2010-09-29 John Mcleod

We introduce a two-parameter function $\phi_{q_+,q_-}$ on the infinite hyperoctahedral group, which is a bivariate refinement of the reflection length keeping track of the long and the short reflections separately. We show that this signed…

Representation Theory · Mathematics 2026-04-14 Marek Bożejko , Maciej Dołęga , Wiktor Ejsmont , Światosław R. Gal

In this work we study representations of certain Coxeter groups to obtain some properties of the corresponding reflection groups.

Group Theory · Mathematics 2020-01-28 François Zara

We introduce a notion of essential hyperbolic Coxeter polytope as a polytope which fits some minimality conditions. The problem of classification of hyperbolic reflection groups can be easily reduced to classification of essential Coxeter…

Combinatorics · Mathematics 2019-10-25 Anna Felikson , Pavel Tumarkin

Given an infinite linear group with a finite set of generators, we show that the shortest word length of an element of infinite order has an upper bound that depends only on the number of generators and the degree. This provides a…

Group Theory · Mathematics 2023-09-11 Junho Peter Whang

In a finite Coxeter group $W$ and with two given conjugacy classes of parabolic subgroups $[X]$ and $[Y]$, we count those parabolic subgroups of $W$ in $[Y]$ that are full support, while simultaneously being simple extensions (i.e.,…

Combinatorics · Mathematics 2022-09-14 Theo Douvropoulos

Aiming for a revival of the theory of crystallographic complex reflection groups, we compute (minimal) Coxeter-like reflection presentations for the infinite families of those non-genuine groups which satisfy Steinberg's fixed point…

Group Theory · Mathematics 2025-10-10 Davide Dal Martello

We study and classify a class of representations (called generalized geometric representations) of a Coxeter group of finite rank. These representations can be viewed as a natural generalization of the geometric representation. The…

Representation Theory · Mathematics 2023-12-11 Hongsheng Hu

In the combinatorics of finite finite Coxeter groups, there is a simple formula giving the number of maximal chains of noncrossing partitions. It is a reinterpretation of a result by Deligne which is due to Chapoton, and the goal of this…

Combinatorics · Mathematics 2018-01-09 Matthieu Josuat-Vergès

We prove that even Coxeter groups, whose Coxeter diagrams contain no (4,4,2) triangles, are conjugacy separable. In particular, this applies to all right-angled Coxeter groups or word hyperbolic even Coxeter groups. For an arbitrary Coxeter…

Group Theory · Mathematics 2015-03-27 Pierre-Emmanuel Caprace , Ashot Minasyan

Folding subgroups give a way to realize non-simply-laced Coxeter groups as subgroups of simply-laced Coxeter groups. In this paper, we study how folding subgroups of finite and affine type are distributed length-wise by calculating the…

Combinatorics · Mathematics 2026-05-13 Camilo Augusto Villamil Chalarca , Edward Richmond