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Related papers: Braid variety cluster structures, II: general type

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We associate a family of cluster X-varieties to the dual Poisson-Lie group G* of a complex semi-simple Lie group G of adjoint type given with the standard Poisson structure. This family is described by the W-permutohedron associated to the…

Representation Theory · Mathematics 2010-05-31 Renaud Brahami

We present here two detailed examples of additive categorifications of the cluster algebra structure of a coordinate ring of a maximal unipotent subgroup of a simple Lie group. The first one is of simply-laced type ($A_3$) and relies on an…

Representation Theory · Mathematics 2017-01-27 Laurent Demonet

We describe presentations of braid groups of type $A$ arising from coloured quivers of mutation type $A$. We show that these can be interpreted geometrically as generalised triangulations of regular polygons.

Group Theory · Mathematics 2023-01-09 Davide Morigi

Leclerc constructed a conjectural cluster structure on Richardson varieties in simply laced types using cluster categories. We show that in type A, his conjectural cluster structure is in fact a cluster structure. We do this by comparing…

Combinatorics · Mathematics 2022-10-25 Khrystyna Serhiyenko , Melissa Sherman-Bennett

We compute the cohomologies of two strand braid varieties using the two-form present in cluster structures. We confirm these results with proof using Alexander and Poincar\'e duality. Further, we consider products of braid varieties and…

Algebraic Geometry · Mathematics 2024-03-25 Tonie Scroggin

We define geodesic normal forms for the general series of complex reflection groups G(e,e,n). This requires the elaboration of a combinatorial technique in order to explicitly determine minimal word representatives of the elements of…

Group Theory · Mathematics 2018-10-24 Georges Neaime

The main goal of this paper is to show that the (multi-homogeneous) coordinate ring of a partial flag variety $\mathbb{C} [G / P_K^{-}]$ admits a cluster algebra structure if $G$ is any simply-connected semisimple complex algebraic group.…

Rings and Algebras · Mathematics 2022-08-30 Fayadh Kadhem

We introduce a Poisson variety compatible with a cluster algebra structure and a compatible toric action on this variety. We study Poisson and topological properties of the union of generic orbits of this toric action. In particular, we…

Quantum Algebra · Mathematics 2007-05-23 M. Gekhtman , M. Shapiro , A. Vainshtein

This paper continues the study of cluster algebras initiated in math.RT/0104151. Its main result is the complete classification of the cluster algebras of finite type, i.e., those with finitely many clusters. This classification turns out…

Rings and Algebras · Mathematics 2015-06-26 Sergey Fomin , Andrei Zelevinsky

We describe a framework for encoding cluster combinatorics using categorical methods. We give a definition of an abstract cluster structure, which captures the essence of cluster mutation at a tropical level and show that cluster algebras,…

Rings and Algebras · Mathematics 2025-10-06 Jan E. Grabowski , Sira Gratz

In the present paper we examine the relationship between several type $A$ cluster theories and structures. We define a 2D geometric model of a cluster theory, which generalizes cluster algebras from surfaces, and encode several existing…

Representation Theory · Mathematics 2022-01-03 Job Daisie Rock

Following an idea of Gon\c{c}alvez, Guaschi and Ocampo on the usual braid group we construct crystallographic and Bieberbach groups as (sub)quotients of the generalized braid group associated to an arbitrary complex reflection group.

Group Theory · Mathematics 2015-12-29 Ivan Marin

A cluster algebra is a commutative algebra whose structure is decided by a skew-symmetrizable matrix or a quiver. When a skew-symmetrizable matrix is invariant under an action of a finite group and this action is admissible, the folded…

Combinatorics · Mathematics 2022-08-31 Byung Hee An , Eunjeong Lee

A result of Allock [1](arXiv:math/9907194) states that certain orbifold braid groups contain Artin groups of type $D_n$, $\tilde{B}_n$ and $\tilde{D}_n$ as finite index subgroups. The underlying orbifolds have at most two cone points of…

Group Theory · Mathematics 2023-12-19 Jonas Flechsig

In this paper, we prove some combinatorial results on generalized cluster algebras. To be more precisely, we prove that (i) the seeds of a generalized cluster algebra $\mathcal A(\mathcal S)$ whose clusters contain particular cluster…

Rings and Algebras · Mathematics 2019-10-09 Peigen Cao , Fang Li

We prove that the pure braid groups on closed, orientable surfaces are bi-orderable, and that the pure braid groups on closed, non-orientable surfaces have generalized torsion, thus they are not bi-orderable.

Geometric Topology · Mathematics 2007-05-23 Juan Gonzalez-Meneses

Let G be a graph. The (unlabeled) configuration space of n points on G is the space of all n-element subsets of G. The fundamental group of such a configuration space is called a graph braid group. We use a version of discrete Morse theory…

Group Theory · Mathematics 2011-10-13 Daniel Farley , Lucas Sabalka

We classify homomorphisms from the braid group on $n$ strands to the pure mapping class group of a nonoriantable surface of genus $g$. For $n\ge 14$ and $g\le 2\lfloor{n/2}\rfloor+1$ every such homomorphism is either cyclic, or it maps…

Geometric Topology · Mathematics 2025-07-18 Michał Stukow , Błażej Szepietowski

While the projections of Schubert varieties in a full generalized flag manifold G/B to a partial flag manifold $G/P$ are again Schubert varieties, the projections of Richardson varieties (intersections of Schubert varieties with opposite…

Algebraic Geometry · Mathematics 2011-09-02 Allen Knutson , Thomas Lam , David E Speyer

In our preceding papers we started considering the categories of tangles with flat G-connections in their complements, where G is a simple complex algebraic group. The braiding (or the commutativity constraint) in such categories satisfies…

Quantum Algebra · Mathematics 2007-05-23 R. Kashaev , N. Reshetikhin