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Related papers: The Hurwitz action in complex reflection groups

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We provide a variety of cases in which two factorizations have Hurwitz orbits of the same size. We begin with prototypical results about factorizations of length two, and show that cycling elements or flipping and inverting elements in any…

Combinatorics · Mathematics 2022-09-05 Colin Pirillo , Seth Sabar

We are extending results from \cite{B-Hurwitz} by building a parallel theory of simple Hurwitz numbers for the reflection groups $G(m,1,n)$. We also study analogs of the cut-and-join operators. An algebraic description as well as a…

Combinatorics · Mathematics 2024-03-05 Raphaël Fesler , Denis Gorodkov , Maksim Karev

We show that if a tuple of Euclidean reflections has a finite orbit under the Hurwitz action of the Artin braid group, then the group generated by these reflections is finite. Humphries has published a similar statement but his proof is…

Algebraic Geometry · Mathematics 2007-05-23 Jean Michel

We consider large finite group-actions on surfaces and discuss and compare various notions for such actions: Hurwitz actions and Hurwitz groups; maximal reducible and completely reducible actions; bounding and geometrically bounding…

Geometric Topology · Mathematics 2024-02-19 Bruno P. Zimmermann

We continue the study of extended Weyl groups $W$, which are reflection groups. Further we recall the definition of a hyperbolic cover of an extended Weyl group, and show that the hyperbolic covers of the extended Weyl groups are extended…

Representation Theory · Mathematics 2025-08-12 Barbara Baumeister , Patrick Wegener , Sophiane Yahiatene

For well-generated complex reflection groups, Chapuy and Stump gave a simple product for a generating function counting reflection factorizations of a Coxeter element by their length. This is refined here to record the number of reflections…

Combinatorics · Mathematics 2017-08-22 Elise delMas , Thomas Hameister , Victor Reiner

Let $G$ be a semisimple algebraic group whose decomposition into a product of simple components does not contain simple groups of type $A$, and $P\subseteq G$ be a parabolic subgroup. Extending the results of Popov [7], we enumerate all…

Algebraic Geometry · Mathematics 2015-10-12 Rostislav Devyatov

We estimate the frequency of polynomial iterations which falls in a given multiplicative subgroup of a finite field of $p$ elements. We also give a lower bound on the size of the subgroup which is multiplicatively generated by the first $N$…

Number Theory · Mathematics 2019-09-12 László Mérai , Igor E. Shparlinski

Reflection groups, geometry of the discriminant and noncrossing partitions. When W is a well-generated complex reflection group, the noncrossing partition lattice NCP_W of type W is a very rich combinatorial object, extending the notion of…

Group Theory · Mathematics 2010-10-22 Vivien Ripoll

In this paper, we count factorizations of Coxeter elements in well-generated complex reflection groups into products of reflections. We obtain a simple product formula for the exponential generating function of such factorizations, which is…

Combinatorics · Mathematics 2015-06-12 Guillaume Chapuy , Christian Stump

We introduce a new class of reflection groups associated with the canonical bilinear lattices of Lenzing, which we call reflection groups of canonical type. The main result of this work is a categorification of the corresponding poset of…

Representation Theory · Mathematics 2025-12-02 Barbara Baumeister , Igor Burban , Georges Neaime , Charly Schwabe

Let $(\mathcal{V},\mathcal{W};F)$ be a weakly reducible, unstabilized, Heegaard splitting of genus at least three in an orientable, irreducible $3$-manifold $M$. Then $Mod(M,F)$ naturally acts on the disk complex $\mathcal{D}(F)$ as a group…

Geometric Topology · Mathematics 2017-09-06 Jungsoo Kim

We extend the usual notion of fully commutative elements from the Coxeter groups to the complex reflection groups. Then we decompose the sets of fully commutative elements into natural subsets according to their combinatorial properties,…

Group Theory · Mathematics 2018-08-14 Gabriel Feinberg , Sungsoon Kim , Kyu-Hwan Lee , Se-jin Oh

In [11] we showed that a loop in a simply connected compact Lie group $\dot{U}$ has a unique Birkhoff (or triangular) factorization if and only if the loop has a unique root subgroup factorization (relative to a choice of a reduced sequence…

Representation Theory · Mathematics 2017-07-05 Arlo Caine , Doug Pickrell

We study the class of all algebras that are isotopic to a Hurwitz algebra. Isomorphism classes of such algebras are shown to correspond to orbits of a certain group action. A complete, geometrically intuitive description of the category of…

Rings and Algebras · Mathematics 2018-08-13 Erik Darpö

In this paper, we study modular categories whose Galois group actions on their simple objects are transitive. We show that such modular categories admit unique factorization into prime transitive factors. The representations of…

Quantum Algebra · Mathematics 2022-04-12 Siu-Hung Ng , Yilong Wang , Qing Zhang

We introduce a natural structure of a semigroup (isomorphic to a factorization semigroup of the unity in the symmetric group) on the set of irreducible components of Hurwitz space of marked degree $d$ coverings of $\mathbb P^1$ of fixed…

Algebraic Geometry · Mathematics 2015-05-18 Vik. S. Kulikov

We shed some light on the problem of determining the orbits of the braid group action on semiorthonormal bases of Mukai lattices as considered in \cite{GK04} and \cite{GO1}. We show that there is an algebraic (and in particular algorithmic)…

Algebraic Geometry · Mathematics 2007-05-23 Amiel Ferman

We investigate the Hurwitz action of the $m$-braid group on the $m$-fold Cartesian product of the universal dihedral quandle. We introduce three computable invariants and prove that they give a complete classification of the orbits under…

Geometric Topology · Mathematics 2026-03-20 Takuji Nakamura , Yasutaka Nakanishi , Shin Satoh , Kodai Wada

We investigate properties of finite transitive permutation groups $(G, \Omega)$ in which all proper subgroups of $G$ act intransitively on $\Omega.$ In particular, we are interested in reduction theorems for minimally transitive…

Group Theory · Mathematics 2007-05-23 Francesca Dalla Volta , Johannes Siemons