Results 1 to 10 of about 15,709 (204)

Coxeter-like complexes [PDF]

open access: diamondDiscrete Mathematics & Theoretical Computer Science, 2004
Motivated by the Coxeter complex associated to a Coxeter system (W,S), we introduce a simplicial regular cell complex Δ(G,S) with a G-action associated to any pair (G,S) where G is a group and S is a finite set of generators for G which is ...
Eric Babson, Victor Reiner
doaj   +7 more sources

A two-sided analogue of the Coxeter complex [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2020
For any Coxeter system (W, S) of rank n, we introduce an abstract boolean complex (simplicial poset) of dimension 2n − 1 which contains the Coxeter complex as a relative subcomplex.
T. Kyle Petersen
doaj   +5 more sources

Submaximal factorizations of a Coxeter element in complex reflection groups [PDF]

open access: diamondDiscrete Mathematics & Theoretical Computer Science, 2011
When $W$ is a finite reflection group, the noncrossing partition lattice $NC(W)$ of type $W$ is a very rich combinatorial object, extending the notion of noncrossing partitions of an $n$-gon.
Vivien Ripoll
doaj   +2 more sources

Coxeter submodular functions and deformations of Coxeter permutahedra

open access: yesAdvances in Mathematics, 2020
We describe the cone of deformations of a Coxeter permutahedron, or equivalently, the nef cone of the toric variety associated to a Coxeter complex. This family of polytopes contains polyhedral models for the Coxeter-theoretic analogs of compositions ...
Federico Ardila
exaly   +3 more sources

Parabolic double cosets in Coxeter groups [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2020
Parabolic subgroups WI of Coxeter systems (W,S) and their ordinary and double cosets W/WI and WI\W/WJ appear in many contexts in combinatorics and Lie theory, including the geometry and topology of generalized flag varieties and the symmetry groups of ...
Sara Billey   +4 more
doaj   +1 more source

On non-conjugate Coxeter elements in well-generated reflection groups [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2015
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 ...
Victor Reiner   +2 more
doaj   +1 more source

Affine descents and the Steinberg torus [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2008
Let $W \ltimes L$ be an irreducible affine Weyl group with Coxeter complex $\Sigma$, where $W$ denotes the associated finite Weyl group and $L$ the translation subgroup. The Steinberg torus is the Boolean cell complex obtained by taking the quotient of $\
Kevin Dilks   +2 more
doaj   +1 more source

Completely positive maps for imprimitive complex reflection groups

open access: yesKarpatsʹkì Matematičnì Publìkacìï, 2021
In 1994, M. Bożejko and R. Speicher proved the existence of completely positive quasimultiplicative maps from the group algebra of Coxeter groups to the set of bounded operators.
H. Randriamaro
doaj   +1 more source

The module of affine descents [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2013
The goal of this paper is to introduce an algebraic structure on the space spanned by affine descent classes of a Weyl group, by analogy and in relation to the structure carried by ordinary descent classes.
Marcelo Aguiar, Kile T. Petersen
doaj   +1 more source

Symmetric Chain Decompositions and the Strong Sperner Property for Noncrossing Partition Lattices [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2020
We prove that the noncrossing partition lattices associated with the complex reflection groups G(d, d, n) for d, n ≥ 2 admit a decomposition into saturated chains that are symmetric about the middle ranks.
Henri Mühle
doaj   +1 more source

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