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Related papers: Bargain hunting in a Coxeter group

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For a finite Coxeter group $W$ and $w$ an element of $W$ the `excess' of $w$ is defined to be $e(w) = \min\{\ell(x) + \ell(y) - \ell(w) \; | \; w=xy, \; x^2 = y^2 = 1\}$ where $\ell$ is the length function on $W$. Here we investigate the…

Group Theory · Mathematics 2014-05-13 Sarah B. Hart , Peter J. Rowley

In this article, we discuss the notion of partition of elements in an arbitrary Coxeter system $(W,S)$: a partition of an element $w$ is a subset $\mathcal P\subseteq W$ such that the left inversion set of $w$ is the disjoint union of the…

Combinatorics · Mathematics 2026-03-13 Christophe Hohlweg , Viviane Pons

Orbits of the Weyl reflection groups attached to the simple Lie groups $A_2, C_2, G_2$ and Coxeter group $H_2$ are considered. For each of the groups products of any two orbits are decomposed into the union of the orbits. Results are…

Mathematical Physics · Physics 2014-02-18 Agnieszka Tereszkiewicz

Assuming standard conjectures, we show that the canonical symmetrizing trace evaluated at powers of a Coxeter element produces rational Catalan numbers for irreducible spetsial complex reflection groups. This extends a technique used by…

Representation Theory · Mathematics 2023-10-20 Weston Miller

We give formulas for the second and third integral homology of an arbitrary finitely generated Coxeter group, solely in terms of the corresponding Coxeter diagram. The first of these calculations refines a theorem of Howlett, while the…

Algebraic Topology · Mathematics 2020-11-11 Rachael Boyd

We present a simple formula for the expected number of inversions in a permutation of size $n$ obtained by applying $t$ random (not necessarily adjacent) transpositions to the identity permutation. More general, for any finite irreducible…

Combinatorics · Mathematics 2010-11-25 Jonas Sjostrand

Given an irreducible well-generated complex reflection group W with Coxeter number h, we call a Coxeter element any regular element (in the sense of Springer) of order h in W; this is a slight extension of the most common notion of Coxeter…

Combinatorics · Mathematics 2014-12-16 Victor Reiner , Vivien Ripoll , Christian Stump

In a recent paper we claimed that both the group algebra of a finite Coxeter group $W$ as well as the Orlik-Solomon algebra of $W$ can be decomposed into a sum of induced one-dimensional representations of centralizers, one for each…

Representation Theory · Mathematics 2011-06-14 J. Matthew Douglass , Goetz Pfeiffer , Gerhard Roehrle

We prove universal (case-free) formulas for the weighted enumeration of factorizations of Coxeter elements into products of reflections valid in any well-generated reflection group $W$, in terms of the spectrum of an associated operator,…

Combinatorics · Mathematics 2023-06-14 Guillaume Chapuy , Theo Douvropoulos

We present a method of computing elements of spin groups in the case of arbitrary dimension. This method generalizes Hestenes method for the case of dimension 4. We use the method of averaging in Clifford's geometric algebra previously…

Mathematical Physics · Physics 2020-03-03 D. S. Shirokov

We refine a conjecture by Lehrer and Solomon on the structure of the Orlik-Solomon algebra of a finite Coxeter group $W$ and relate it to the descent algebra of $W$. As a result, we claim that both the group algebra of $W$, as well as the…

Representation Theory · Mathematics 2013-03-11 J. Matthew Douglass , Goetz Pfeiffer , Gerhard Roehrle

We combinatorially characterize the number $\mathrm{cc}_2$ of conjugacy classes of involutions in any Coxeter group in terms of higher rank odd graphs. This notion naturally generalizes the concept of odd graphs, used previously to count…

Group Theory · Mathematics 2025-06-10 Anna Michael , Yuri Santos Rego , Petra Schwer , Olga Varghese

This paper presents a natural generalisation of Saxl conjecture from a Lie-theoretical perspective, which is verified for the exceptional types. For classical types, progress is made using spin representations, revealing connections to…

Representation Theory · Mathematics 2024-09-27 Yutong Chen , Felix Gu , Will Osborne

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

Real physical systems with reflective and rotational symmetries such as viruses, fullerenes and quasicrystals have recently been modeled successfully in terms of three-dimensional (affine) Coxeter groups. Motivated by this progress, we…

Mathematical Physics · Physics 2016-07-13 Pierre-Philippe Dechant

Let $W_a$ be an affine Weyl group and $\eta:W_a\longrightarrow W_0$ be the natural projection to the corresponding finite Weyl group. We say that $w\in W_a$ has finite Coxeter part if $\eta(w)$ is conjugate to a Coxeter element of $W_0$.…

Representation Theory · Mathematics 2012-03-22 Xuhua He , Zhongwei Yang

We find a simple product formula for the characteristic polynomial of the permutations with a fixed descent set under the weak order. As a corollary we obtain a simple product formula for the characteristic polynomial of alternating…

Combinatorics · Mathematics 2022-04-05 Jang Soo Kim , Sun-mi Yun

A Coxeter group W is called reflection independent if its reflections are uniquely determined by W only, independently on the choice of the generating set. We give a new sufficient condition for the reflection independence, and examine this…

Group Theory · Mathematics 2007-05-23 Koji Nuida

In a finite real reflection group, the reflection length of each element is equal to the codimension of its fixed space, and the two coincident functions determine a partial order structure called the absolute order. In complex reflection…

Combinatorics · Mathematics 2025-05-20 Joel Brewster Lewis , Jiayuan Wang

We present new efficient data structures for elements of Coxeter groups of type $A_m$ and their associated Iwahori--Hecke algebras $H(A_m)$. Usually, elements of $H(A_m)$ are represented as simple coefficient list of length $M = (m+1)!$…

Group Theory · Mathematics 2016-09-16 Alice C. Niemeyer , Götz Pfeiffer , Cheryl E. Praeger