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Related papers: Affine and cyclotomic Schur categories

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Using combinatorial properties of symmetric polynomials, we compute explicitly the Soergel modules for some permutations whose corresponding Schubert varieties are rationally smooth. We build from them diagram algebras whose module…

Representation Theory · Mathematics 2013-11-28 Antonio Sartori

We define higher Frobenius-Schur indicators for objects in linear pivotal monoidal categories. We prove that they are category invariants, and take values in the cyclotomic integers. We also define a family of natural endomorphisms of the…

Quantum Algebra · Mathematics 2015-11-13 Siu-Hung Ng , Peter Schauenburg

In this paper, we introduce the category of blueprints, which is a category of algebraic objects that include both commutative (semi)rings and commutative monoids. This generalization allows a simultaneous treatment of ideals resp.\…

Algebraic Geometry · Mathematics 2012-01-09 Oliver Lorscheid

Bimonoidal categories (also known as rig categories) are categories with two monoidal structures, one of which distributes over the other. We formally define sheet diagrams, a graphical calculus for bimonoidal categories that was informally…

Category Theory · Mathematics 2020-12-22 Cole Comfort , Antonin Delpeuch , Jules Hedges

We provide an affine cellular structure on the extended affine Hecke algebra and affine $q$-Schur algebra of type $A_{n-1}$ that is defined over $\mathbb{Z}\left[q^{\pm1}\right]$, that is, without an adjoined $q^{\frac{1}{2}}$. This is with…

Representation Theory · Mathematics 2026-01-08 Rose Berry

We develop a graded version of the theory of cyclotomic q-Schur algebras, in the spirit of the work of Brundan-Kleshchev on Hecke algebras and of Ariki on q-Schur algebras. As an application, we identify the coefficients of the canonical…

Rings and Algebras · Mathematics 2014-07-17 Catharina Stroppel , Ben Webster

We introduce two 2-categories which categorify the monodromic Hecke algebra. The first is algebraic in nature and generalizes Abe's theory of Soergel bimodules. The second is a diagrammatic category defined via generators and relations…

Representation Theory · Mathematics 2026-04-20 Colton Sandvik

The affine quantum Schur algebra is a certain important infinite dimensional algebra whose representation theory is closely related to that of quantum affine $\frak{gl}_n$. Finite dimensional irreducible modules for the affine quantum Schur…

Representation Theory · Mathematics 2013-04-23 Qiang Fu

The geometric and algebraic properties of Gray categories with duals are investigated by means of a diagrammatic calculus. The diagrams are three-dimensional stratifications of a cube, with regions, surfaces, lines and vertices labelled by…

Quantum Algebra · Mathematics 2024-09-24 John W. Barrett , Catherine Meusburger , Gregor Schaumann

The k-Schur functions were first introduced by Lapointe, Lascoux and Morse (2003) in the hopes of refining the expansion of Macdonald polynomials into Schur functions. Recently, an alternative definition for k-Schur functions was given by…

Combinatorics · Mathematics 2020-03-05 Sami Assaf , Sara Billey

We introduce the oriented Brauer-Clifford and degenerate affine oriented Brauer-Clifford supercategories. These are diagrammatically defined monoidal supercategories which provide combinatorial models for certain natural monoidal…

Representation Theory · Mathematics 2023-09-13 Jonathan Brundan , Jonathan Comes , Jonathan R. Kujawa

We construct a diagrammatic categorification of the spherical module over the Hecke algebra. We establish a basis for the morphism spaces of this category, and prove that it is equivalent to an existing algebraic spherical category.

Representation Theory · Mathematics 2026-03-06 Tasman Fell

The degenerate affine and affine BMW algebras arise naturally in the context of Schur-Weyl duality for orthogonal and symplectic Lie algebras and quantum groups, respectively. Cyclotomic BMW algebras, affine Hecke algebras, cyclotomic Hecke…

Representation Theory · Mathematics 2011-08-04 Zajj Daugherty , Arun Ram , Rahbar Virk

We define the affine Frobenius Brauer categories associated to each symmetric involutive Frobenius superalgebra $A$. We then define an action of these categories on the categories of finite-dimensional supermodules for orthosymplectic Lie…

Representation Theory · Mathematics 2025-09-22 Saima Samchuck-Schnarch

We study the Schur elements and the a-function for cyclotomic Hecke algebras. As a consequence, we show the existence of canonical basic sets, as defined by Geck-Rouquier, for certain complex reflection groups. This includes the case of…

Representation Theory · Mathematics 2009-10-27 Maria Chlouveraki , Nicolas Jacon

We introduce a new diagrammatic $\Bbbk$-linear monoidal supercategory $QWeb^\bullet$, the affine web supercategory of type $Q$, where $\Bbbk$ is a commutative ring of characteristic not two. This category is the affinization of the web…

Representation Theory · Mathematics 2025-06-24 Linliang Song , Xingyu Wang

We introduce a diagrammatic monoidal category, the spin Brauer category, that plays the same role for the spin and pin groups as the Brauer category does for the orthogonal groups. In particular, there is a full functor from the spin Brauer…

Representation Theory · Mathematics 2025-05-14 Peter J. McNamara , Alistair Savage

We apply crystal theory to affine Schubert calculus, Gromov-Witten invariants for the complete flag manifold, and the positroid stratification of the positive Grassmannian. We introduce operators on decompositions of elements in the…

Combinatorics · Mathematics 2016-06-02 Jennifer Morse , Anne Schilling

The cohomology of the affine flag variety of a complex reductive group is a comodule over the cohomology of the affine Grassmannian. We give positive formulae for the coproduct of an affine Schubert class in terms of affine Stanley classes…

Combinatorics · Mathematics 2020-09-22 Thomas Lam , Seung Jin Lee , Mark Shimozono

We give a criterion for a collection of polynomials to be a universal Gr\"{o}bner basis for an ideal in terms of the multidegree of the closure of the corresponding affine variety in $(\mathbb{P}^1)^N$. This criterion can be used to give…

Algebraic Geometry · Mathematics 2024-11-27 Daoji Huang , Matt Larson