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Related papers: A categorification of non-crossing partitions

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We classify t-structures and thick subcategories in discrete cluster categories $\mathcal{C}(\mathcal{Z})$ of Dynkin type $A$, and show that the set of all t-structures on $\mathcal{C}(\mathcal{Z})$ is a lattice under inclusion of aisles,…

Representation Theory · Mathematics 2022-12-29 Sira Gratz , Alexandra Zvonareva

We define a new lattice structure on the elements of a finite Coxeter group W. This lattice, called the shard intersection order, is weaker than the weak order and has the noncrossing partition lattice NC(W) as a sublattice. The new…

Combinatorics · Mathematics 2026-05-14 Nathan Reading

Let $\mathcal{L}$ be the noncrossing partition lattice associated to a finite Coxeter group $W$. In this paper we construct explicit bases for the top homology groups of intervals and rank-selected subposets of $\mathcal{L}$. We define a…

Combinatorics · Mathematics 2023-01-26 Yang Zhang

This memoir constitutes the author's PhD thesis at Cornell University. It serves both as an expository work and as a description of new research. At the heart of the memoir, we introduce and study a poset $NC^{(k)}(W)$ for each finite…

Combinatorics · Mathematics 2007-10-19 Drew Armstrong

Introduced by Reading, the shard intersection order of a finite Coxeter group $W$ is a lattice structure on the elements of $W$ that contains the poset of noncrossing partitions $NC(W)$ as a sublattice. Building on work of Bancroft in the…

Combinatorics · Mathematics 2013-06-18 T. Kyle Petersen

We introduce a new basis of the Temperley-Lieb algebra. It is defined using a bijection between noncrossing partitions and fully commutative elements together with a basis introduced by Zinno, which is obtained by mapping the simple…

Quantum Algebra · Mathematics 2015-08-18 Thomas Gobet

We use the characteristic polynomial of the Coxeter matrix of an algebra to complete the combinatorial classification of piecewise hereditary algebras which Happel gave in terms of the trace of the Coxeter matrix. We also give a…

Representation Theory · Mathematics 2009-03-26 Marcelo Lanzilotta , Maria Julia Redondo , Rachel Taillefer

This paper generalizes in the affine symmetric group the notion of Coxeter sortable (or c-sortable for short) elements, as well as the classical bijection between c-sortable elements and c-noncrossing partitions defined by Reading in finite…

Combinatorics · Mathematics 2026-05-05 Jad Abou-Yassin

Higher-order notions of Kreweras complementation have appeared in the literature in the works of Krawczyk, Speicher, Mastnak, Nica, Arizmendi, Vargas, and others. While the theory has been developed primarily for specific applications in…

Combinatorics · Mathematics 2025-08-26 Kurusch Ebrahimi-Fard , Loïc Foissy , Joachim Kock , Frédéric Patras

Let W be a finite crystallographic reflection group. The generalized Catalan number of W coincides both with the number of clusters in the cluster algebra associated to W, and with the number of noncrossing partitions for W. Natural…

Representation Theory · Mathematics 2011-06-15 Aslak Bakke Buan , Idun Reiten , Hugh Thomas

In [17], we introduced ``picture groups'' and computed the cohomology of the picture group of type $A_n$. This is the same group what was introduced by Loday [20] where he called it the ``Stasheff group''. In this paper, we give an…

Representation Theory · Mathematics 2025-03-25 Kiyoshi Igusa

We introduce and study the model of simply generated non-crossing partitions, which are, roughly speaking, chosen at random according to a sequence of weights. This framework encompasses the particular case of uniform non-crossing…

Probability · Mathematics 2017-06-30 Igor Kortchemski , Cyril Marzouk

Motivated by recent work on mixtures of classical and free probabilities, we introduce and study the notion of $\epsilon$-noncrossing partitions. It is shown that the set of such partitions forms a lattice, which interpolates as a poset…

Combinatorics · Mathematics 2018-12-06 Kurusch Ebrahimi-Fard , Frederic Patras , Roland Speicher

We realize the crystal associated to the quantized enveloping algebras with a symmetric generalized Cartan matrix as a set of Lagrangian subvarieties of the cotangent bundle of the quiver variety. As a by-product, we give a counterexample…

q-alg · Mathematics 2015-12-22 Masaki Kashiwara , Yoshihisa Saito

We give a combinatorial model for the bounded derived category of graded modules over the dual numbers in terms of arcs on the integer line with a point at infinity. Using this model we describe the lattice of thick subcategories of the…

Representation Theory · Mathematics 2016-11-08 Sira Gratz , Greg Stevenson

Following an idea of A. Berenstein, we define a commutor for the category of crystals of a finite dimensional complex reductive Lie algebra. We show that this endows the category of crystals with the structure of a coboundary category.…

Quantum Algebra · Mathematics 2007-05-23 Andre Henriques , Joel Kamnitzer

When W is a finite reflection group, the noncrossing partition lattice NCP_W of type W is a rich combinatorial object, extending the notion of noncrossing partitions of an n-gon. A formula (for which the only known proofs are case-by-case)…

Combinatorics · Mathematics 2014-06-10 Vivien Ripoll

In 2007, D.I. Panyushev defined a remarkable map on the set of nonnesting partitions (antichains in the root poset of a finite Weyl group). In this paper we identify Panyushev's map with the Kreweras complement on the set of noncrossing…

Combinatorics · Mathematics 2011-03-10 Drew Armstrong , Christian Stump , Hugh Thomas

Although both noncrossing partitions and nonnesting partitions are uniformly enumerated for Weyl groups, the exact relationship between these two sets of combinatorial objects remains frustratingly mysterious. In this paper, we give a…

Let Q be a Dynkin quiver. The bounded derived category of the path algebra of Q has an autoequivalence given by the composition of the Auslander-Reiten translate and the square of the shift functor. We study maximal Hom-free sets in the…

Representation Theory · Mathematics 2010-12-07 Raquel Coelho Simoes