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Related papers: Reflection length in non-affine Coxeter groups

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We give uniform formulas for the number of full reflection factorizations of a parabolic quasi-Coxeter element in a Weyl group or complex reflection group, generalizing the formula for the genus-0 Hurwitz numbers. This paper is the…

Combinatorics · Mathematics 2025-05-20 Theo Douvropoulos , Joel Brewster Lewis , Alejandro H. Morales

The isomorphism problem for Coxeter groups has been reduced to its 'reflection preserving version' by B. Howlett and the second author. Thus, in order to solve it, it suffices to determine for a given Coxeter system (W,R) all Coxeter…

Group Theory · Mathematics 2014-10-01 Timothée Marquis , Bernhard Mühlherr

Petersen and Tenner defined the depth statistic for Coxeter group elements which, in the symmetric group, can be described in terms of a cost function on transpositions. We generalize that cost function to the other classical (finite and…

Combinatorics · Mathematics 2024-02-07 Joel Brewster Lewis , Bridget Eileen Tenner

In this article we calculate the minimal faithful permutation degree for all of the irreducible Coxeter groups. We also exhibit new examples of finite groups that possess a quotient whose minimal degree is strictly greater than that of the…

Group Theory · Mathematics 2014-03-24 Neil Saunders

We continue the study of freely braided elements of simply laced Coxeter groups, which we introduced in a previous work (math.CO/0301104). A known upper bound for the number of commutation classes of reduced expressions for an element of a…

Combinatorics · Mathematics 2007-05-23 R. M. Green , J. Losonczy

We study stable commutator length on free $\mathbb{Q}$-groups. We prove that every non-identity element has positive stable commutator length, and that the corresponding free group embeds isometrically. We deduce that a non-abelian free…

Group Theory · Mathematics 2025-12-02 Francesco Fournier-Facio

This paper concerns preprojective representations of a finite connected valued quiver without oriented cycles. For each such representation, an explicit formula in terms of the geometry of the quiver gives a unique, up to a certain…

Representation Theory · Mathematics 2007-05-23 Mark Kleiner , Helene R. Tyler

We investigate the so-called dual Matsumoto property or Hurwitz action in finite, affine and arbitrary Coxeter groups. In particular, we want to investigate how to reduce reflection factorizations and how two reflection factorizations of…

Group Theory · Mathematics 2021-10-28 Patrick Wegener , Sophiane Yahiatene

We show that the minimal number of generators and the Cohen-Macaulay type of a family of numerical semigroups generated by concatenation of arithmetic sequences is unbounded.

Commutative Algebra · Mathematics 2022-03-01 Ranjana Mehta , Joydip Saha , Indranath Sengupta

We prove that the irreducible affine Coxeter groups are first-order rigid and deduce from this that they are profinitely rigid in the absolute sense. We then show that the first-order theory of any irreducible affine Coxeter group does not…

Group Theory · Mathematics 2024-07-03 Gianluca Paolini , Rizos Sklinos

We give necessary and sufficient conditions for a linear reflection group in the sense of Vinberg to be Zariski-dense in the ambient projective general linear group. As an application, we show that every irreducible right-angled Coxeter…

Geometric Topology · Mathematics 2025-04-03 Jacques Audibert , Sami Douba , Gye-Seon Lee , Ludovic Marquis

In this paper, we study the generating function of cyclically fully commutative elements in Coxeter groups, which are elements such that any cyclic shift of theirs reduced decompositions remains a reduced expression of a fully commutative…

Combinatorics · Mathematics 2016-12-13 Mathias Pétréolle

We consider the automorphism groups of various Lorentzian lattices over the Eisenstein, Gaussian, and Hurwitz integers, and in some of them we find reflection groups of finite index. These provide new finite-covolume reflection groups…

Group Theory · Mathematics 2007-05-23 Daniel Allcock

Let $(W,R)$ be an arbitrary Coxeter system. We determine the number of elements of $W$ that have a unique reduced expression.

Group Theory · Mathematics 2017-01-09 Sarah Hart

We show that in the complex reflection group $G_6$, reflection factorizations of a Coxeter element that have the same length and multiset of conjugacy classes are in the same Hurwitz orbit. This confirms one case of a conjecture of Lewis…

Combinatorics · Mathematics 2022-02-07 Gaurav Gawankar , Dounia Lazreq , Mehr Rai , Seth Sabar

We review the properties of the finite Coxeter groups which are most useful for applications to cohomological invariants, namely their classes of involutions and their "cubes" (abelian subgroups generated by reflections).

Group Theory · Mathematics 2022-04-07 Jean-Pierre Serre

We provide a general construction of convex cocompact hyperbolic reflection groups with three-dimensional limit sets. More precisely, our construction takes as input an arbitrary simplicial complex L of dimension 3 on n vertices, and…

Group Theory · Mathematics 2026-04-02 Sami Douba , Gye-Seon Lee , Ludovic Marquis , Lorenzo Ruffoni

We give a geometric proof that minimal length elements in a (twisted) conjugacy class of a finite Coxeter group $W$ have remarkable properties with respect to conjugation, taking powers in the associated Braid group and taking centralizer…

Representation Theory · Mathematics 2019-12-19 Xuhua He , Sian Nie

Several finite complex reflection groups have a braid group which is isomorphic to a torus knot group. The reflection group is obtained from the torus knot group by declaring meridians to have order $k$ for some $k\geq 2$, and meridians are…

Group Theory · Mathematics 2022-01-19 Thomas Gobet

Suppose $G$ is a simple group. For any nontrivial elements $g$ and $h$, $g$ can be written as a finite product of conjugates of $h$ or the inverse of $h$. G is called uniformly simple if the length of such an expression is uniformly…

Group Theory · Mathematics 2011-07-27 Hiroki Kodama