English
Related papers

Related papers: On inductively free reflection arrangements

200 papers

Let B be the generalized braid group associated to some finite complex reflection group. We define a representation of B of dimension the number of reflections of the corresponding reflection group, which generalizes the Krammer…

Representation Theory · Mathematics 2008-10-04 Ivan Marin

Let $V$ be a finite dimensional complex vector space and $W\subseteq \GL(V)$ be a finite complex reflection group. Let $V^{\reg}$ be the complement in $V$ of the reflecting hyperplanes. We prove that $V^{\reg}$ is a $K(\pi,1)$ space. This…

Geometric Topology · Mathematics 2014-01-24 David Bessis

In this expository note, I showcase the relevance of Coxeter groups to quiver representations. I discuss (1) real and imaginary roots, (2) reflection functors, and (3) torsion free classes and c-sortable elements. The first two topics are…

Representation Theory · Mathematics 2018-03-13 Hugh Thomas

A referee found an error in the proof of the Theorem 2 that we could not fix. More precisely, the proof of Lemma 2.1 is incorrect. Hence the fact that integer cohomology of complement of toric Weyl arrangements is torsion free is still a…

Geometric Topology · Mathematics 2011-12-19 Simona Settepanella

The lattice of intersections of reflecting hyperplanes of a complex reflection group W may be considered as the poset of 1-eigenspaces of the elements of W. In this paper we replace 1 with an arbitrary eigenvalue and study the topology and…

Combinatorics · Mathematics 2012-08-10 Alexander R. Miller

This is the expanded notes of the lecture by the author in "Arrangements in Pyrenees", June 2012. We are discussing relations of freeness and splitting problems of vector bundles, several techniques proving freeness of hyperplane…

Algebraic Geometry · Mathematics 2014-05-26 Masahiko Yoshinaga

The two most fundamental conjectures on the structure of the generic Hecke algebra $\mathcal{H}(W)$ associated with a complex reflection group $W$ state that $\mathcal{H}(W)$ is a free module of rank $|W|$ over its ring of definition, and…

Representation Theory · Mathematics 2022-03-02 Eirini Chavli , Maria Chlouveraki

We introduce a notion of "freely braided element" for simply laced Coxeter groups. We show that an arbitrary group element $w$ has at most $2^{N(w)}$ commutation classes of reduced expressions, where $N(w)$ is a certain statistic defined in…

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

Classical invariant theory of a complex reflection group $W$ highlights three beautiful structures: -- the $W$-invariant polynomials constitute a polynomial algebra, over which -- the $W$-invariant differential forms with polynomial…

Combinatorics · Mathematics 2019-02-05 Victor Reiner , Anne V. Shepler

We exhibit a particular free subarrangement of a certain restriction of the Weyl arrangement of type $E_7$ and use it to give an affirmative answer to a recent conjecture by T.~Abe on the nature of additionally free and stair-free…

Combinatorics · Mathematics 2019-03-06 Torsten Hoge , Gerhard Roehrle

For W a finite (2-)reflection group and B its (generalized) braid group, we determine the Zariski closure of the image of B inside the corresponding Iwahori-Hecke algebra. The Lie algebra of this closure is reductive and generated in the…

Representation Theory · Mathematics 2009-11-11 Ivan Marin

The purpose of this article is to shed new light on the combinatorial structure of Kazhdan-Lusztig cells in infinite Coxeter groups $W$. Our main focus is the set $\D$ of distinguished involutions in $W$, which was introduced by Lusztig in…

Representation Theory · Mathematics 2014-06-16 Mikhail V. Belolipetsky , Paul E. Gunnells

We construct counterexamples to Yoshinaga's conjecture that every free arrangement is either inductively free or rigid in characteristic zero. The smallest example has $13$ hyperplanes, its intersection lattice has a one dimensional moduli…

Combinatorics · Mathematics 2014-06-30 Michael Cuntz

We consider the triple $(\mathcal{A},\mathcal{A}',\mathcal{A}^H)$ of hyperplane arrangements and the division of their characteristic polynomials. We show that the freeness of $\mathcal{A}^H$ and the division of $\chi(\mathcal{A};t)$ by…

Commutative Algebra · Mathematics 2017-01-18 Takuro Abe

We refine Brieskorn's study of the cohomology of the complement of the reflection arrangement of a finite Coxeter group $W$. As a result we complete the verification of a conjecture by Felder and Veselov that gives an explicit basis of the…

Representation Theory · Mathematics 2019-05-14 J. Matthew Douglass , Goetz Pfeiffer , Gerhard Roehrle

Attractor dynamics are a hallmark of many complex systems, including the brain. Understanding how such self-organizing dynamics emerge from first principles is crucial for advancing our understanding of neuronal computations and the design…

Neurons and Cognition · Quantitative Biology 2026-05-22 Tamas Spisak , Karl Friston

Between 1994 and 1998, the work of M. Brou\'e, G. Malle, and R. Rouquier generalized in a natural way the definition of the Hecke algebra associated to a finite Coxeter group, for the case of an arbitrary complex reflection group.…

Representation Theory · Mathematics 2016-08-03 Eirini Chavli

Chain complexes of finitely generated free modules over orbit categories provide natural algebraic models for finite G-CW complexes with prescribed isotropy. We prove a p-hypoelementary Dress induction theorem for K-theory over the orbit…

Algebraic Topology · Mathematics 2013-02-12 Ian Hambleton , Ergun Yalcin

We prove Terao conjecture saying that the freeness is determined by the combinatorics for arrangements of 13 lines in the complex projective plane and that the property of being nearly free is combinatorial for line arrangements of up to 12…

Algebraic Topology · Mathematics 2018-05-03 Alexandru Dimca , Denis Ibadula , Anca Macinic

Some of the most classically relevant Hyperplane arrangements are the Braid Arrangements $B_n$ and their associated compliment spaces $\mathcal{F}_n$. In their recent work, Tsilevich, Vershik, and Yuzvinsky construct what they refer to as…

Combinatorics · Mathematics 2024-06-04 Ian Flynn , Eric Ramos , Benjamin Young