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Related papers: Noncrossing arithmetic

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We define noncrossing partitions of a marked surface without punctures (interior marked points). We show that the natural partial order on noncrossing partitions is a graded lattice and describe its rank function topologically. Lower…

Combinatorics · Mathematics 2026-05-22 Nathan Reading

We consider noncrossing partitions of [n] under the action of (i) the reflection group (of order 2), (ii) the rotation group (cyclic of order n) and (iii) the rotation/reflection group (dihedral of order 2n). First, we exhibit a bijection…

Combinatorics · Mathematics 2007-05-23 David Callan , Len Smiley

In this paper, we study the lattice properties of posets of torsion pairs in the module category of a family of representation-finite gentle algebras called tiling algebras, introduced by Coelho Simoes and Parsons. We present a…

Representation Theory · Mathematics 2016-09-13 Alexander Garver , Thomas McConville

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

A partition on $[n]$ has a crossing if there exists $i\_1<i\_2<j\_1<j\_2$ such that $i\_1$ and $j\_1$ are in the same block, $i\_2$ and $j\_2$ are in the same block, but $i\_1$ and $i\_2$ are not in the same block. Recently, Chen et al.…

Combinatorics · Mathematics 2009-01-23 Mireille Bousquet-Mélou , Guoce Xin

Consider the noncrossing set partitions of an $n$-element set which either do not contain the block $\{n-1,n\}$, or which do not contain the singleton block $\{n\}$ whenever $1$ and $n-1$ are in the same block. In this article we study the…

Combinatorics · Mathematics 2018-09-14 Henri Mühle

The noncrossing partition poset associated to a Coxeter group $W$ and Coxeter element $c$ is the interval $[1,c]_T$ in the absolute order on $W$. We construct a new model of noncrossing partititions for $W$ of classical affine type, using…

Combinatorics · Mathematics 2026-05-13 Laura G. Brestensky , Nathan Reading

We establish recursions counting various classes of chains in the noncrossing partition lattice of a finite Coxeter group. The recursions specialize a general relation which is proven uniformly (i.e. without appealing to the classification…

Combinatorics · Mathematics 2026-05-13 Nathan Reading

We introduce two order relations on finite Coxeter groups which refine the absolute and the Bruhat order, and establish some of their main properties. In particular we study the restriction of these orders to noncrossing partitions and show…

Combinatorics · Mathematics 2021-01-14 Philippe Biane , Matthieu Josuat-Vergès

We study the poset of d-indivisible noncrossing partitions introduced by M\"uhle, Nadeau and Williams. These are noncrossing partitions such that each block has cardinality 1 modulo d and each block of the dual partition also has…

Combinatorics · Mathematics 2024-10-15 Richard Ehrenborg , Gábor Hetyei

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

A weak order on the set of maximal chains of the non-crossing partition lattice is introduced and studied. A $0$-Hecke algebra action is used to compute the radius of the graph on these chains in which two chains are adjacent if they differ…

Combinatorics · Mathematics 2013-12-25 Ron M. Adin , Yuval Roichman

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

The purpose of this note is to complete the study, begun in the first author's PhD thesis, of the topology of the poset of generalized noncrossing partitions associated to real reflection groups. In particular, we calculate the Euler…

Combinatorics · Mathematics 2009-12-05 Drew Armstrong , Christian Krattenthaler

In this paper, we further develop the theory of circles of partition by introducing the notion of complex circles of partition. This work generalizes the classical framework, extending from subsets of the natural numbers as base sets to…

General Mathematics · Mathematics 2026-05-05 Berndt Gensel , Theophilus Agama

The concept of a crossed tensor product of algebras is studied from a few points of views. Some related constructions are considered. Crossed enveloping algebras and their representations are discussed. Applications to the noncommutative…

Mathematical Physics · Physics 2009-10-31 A. Borowiec , W. Marcinek

We situate the noncrossing partitions associated to a finite Coxeter group within the context of the representation theory of quivers. We describe Reading's bijection between noncrossing partitions and clusters in this context, and show…

Representation Theory · Mathematics 2014-01-14 Colin Ingalls , Hugh Thomas

We present a categorification of the non-crossing partitions given by crystallographic Coxeter groups. This involves a category of certain bilinear lattices, which are essentially determined by a symmetrisable generalised Cartan matrix…

Representation Theory · Mathematics 2015-06-09 Andrew Hubery , Henning Krause

The material gives a new combinatorial proof of the multiplicative property of the S-transform. In particular, several properties of the coefficients of its inverse are connected to non-crossing linked partitions and planar trees.

Operator Algebras · Mathematics 2009-01-26 Mihai Popa

Schutzenberger's theorem for the ordinary RSK correspondence naturally extends to Chen et. al's correspondence for matchings and partitions. Thus the counting of bilaterally symmetric $k$-noncrossing partitions naturally arises as an…

Combinatorics · Mathematics 2008-10-09 Guoce Xin , Terence Y. J. Zhang