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Related papers: Catalan functions and $k$-Schur positivity

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We prove that the $K$-$k$-Schur functions are part of a family of inhomogenous symmetric functions whose top homogeneous components are Catalan functions, the Euler characteristics of certain vector bundles on the flag variety.…

Combinatorics · Mathematics 2020-10-06 Jonah Blasiak , Jennifer Morse , George H. Seelinger

Catalan functions, the graded Euler characteristics of certain vector bundles on the flag variety, are a rich class of symmetric functions which include $k$-Schur functions and parabolic Hall-Littlewood polynomials. We prove that Catalan…

Combinatorics · Mathematics 2020-07-13 Jonah Blasiak , Jennifer Morse , Anna Pun

We make a broad conjecture about the $k$-Schur positivity of Catalan functions, symmetric functions which generalize the (parabolic) Hall-Littlewood polynomials. We resolve the conjecture with positive combinatorial formulas in cases which…

Combinatorics · Mathematics 2018-11-07 Jonah Blasiak , Jennifer Morse , Anna Pun , Daniel Summers

We characterize the $k$-Schur functions as the graded characters of simple objects in an additive module category. This confirms a set of conjectures formulated in the Ph.D. thesis of Chen, written under the direction of Mark Haiman, and…

Representation Theory · Mathematics 2025-10-01 Syu Kato

We introduce the new concept of weighted $K$-$k$-Schur functions -- a novel family within the broader class of Katalan functions -- that unifies and extends both $K$-$k$-Schur functions and closed $k$-Schur Katalan functions. This new…

Combinatorics · Mathematics 2025-08-01 Yaozhou Fan , Xing Gao

We prove the conjectures of Graham-Kumar and Griffeth-Ram concerning the alternation of signs in the structure constants for torus-equivariant K-theory of generalized flag varieties G/P. These results are immediate consequences of an…

Algebraic Geometry · Mathematics 2017-03-14 Dave Anderson , Stephen Griffeth , Ezra Miller

We prove Stanley's conjecture that, if delta_n is the staircase shape, then the skew Schur functions s_{delta_n / mu} are non-negative sums of Schur P-functions. We prove that the coefficients in this sum count certain fillings of shifted…

Combinatorics · Mathematics 2011-08-11 Federico Ardila , Luis G. Serrano

Some new relations on skew Schur function differences are established both combinatorially using Sch\"utzenberger's jeu de taquin, and algebraically using Jacobi-Trudi determinants. These relations lead to the conclusion that certain…

Combinatorics · Mathematics 2014-01-30 Ronald C. King , Trevor A. Welsh , Stephanie J. van Willigenburg

We introduce two families of symmetric functions generalizing the factorial Schur $P$- and $Q$- functions due to Ivanov. We call them $K$-theoretic analogues of factorial Schur $P$- and $Q$- functions. We prove various combinatorial…

Combinatorics · Mathematics 2013-05-27 Takeshi Ikeda , Hiroshi Naruse

We give new characterizations of plurisubharmonic functions and Griffiths positivity of holomorphic vector bundles with singular Finsler metrics. As applications, we present a different method to prove plurisubharmonic variation of…

Complex Variables · Mathematics 2018-09-28 Fusheng Deng , Zhiwei Wang , Liyou Zhang , Xiangyu Zhou

We give a combinatorial expansion of a Schubert homology class in the affine Grassmannian Gr_{SL_k} into Schubert homology classes in Gr_{SL_{k+1}}. This is achieved by studying the combinatorics of a new class of partitions called…

Combinatorics · Mathematics 2010-08-02 Thomas Lam , Luc Lapointe , Jennifer Morse , Mark Shimozono

We define a number of related combinatorial objects, each of which possesses a surprising symmetry. We include several applications such as a combinatorial explanation for certain fixed points of the involution $\omega$ on the ring of…

Combinatorics · Mathematics 2018-09-13 Graham Hawkes

We provide the special values of the skew version of the $K$-theoretic Schur $P$- and $Q$-functions. Using these special values, we show an oddness property of the number of shifted set-valued skew tableaux. Additionally, we generalize…

Combinatorics · Mathematics 2025-10-27 Takahiko Nobukawa , Tatsushi Shimazaki

We prove an identity relating the product of two opposite Schubert varieties in the (equivariant) quantum K-theory ring of a cominuscule flag variety to the minimal degree of a rational curve connecting the Schubert varieties. We deduce…

Algebraic Geometry · Mathematics 2018-01-31 Anders Skovsted Buch , Sjuvon Chung

The Schubert bases of the torus-equivariant homology and cohomology rings of the affine Grassmannian of the special linear group are realized by new families of symmetric functions called k-double Schur functions and affine double Schur…

Combinatorics · Mathematics 2011-05-12 Thomas Lam , Mark Shimozono

We suggest the point of view that the Schubert classes of the affine Grassmannian of a simple algebraic group should be considered as Schur-positive symmetric functions. In particular, we give a geometric explanation of the Schur positivity…

Algebraic Geometry · Mathematics 2014-02-26 Thomas Lam

This paper investigates the representation-theoretic structure of the Koszul cohomology of a smooth projective variety $X$ over an algebraically closed field $k$, admitting an action of a finite group $G$ of order coprime to ${\rm…

Algebraic Geometry · Mathematics 2026-02-19 Kostas Karagiannis , Aristides Kontogeorgis , Konstantia Manousou Sotiropoulou

We study k-Schur functions characterized by k-tableaux, proving combinatorial properties such as a k-Pieri rule and a k-conjugation. This new approach relies on developing the theory of k-tableaux, and includes the introduction of a…

Combinatorics · Mathematics 2007-05-23 Luc Lapointe , Jennifer Morse

We derive a $K$-theoretic analogue of the Vafa--Intriligator formula, computing the (virtual) Euler characteristics of vector bundles over the Quot scheme that compactifies the space of degree $d$ morphisms from a fixed projective curve to…

Algebraic Geometry · Mathematics 2024-12-09 Shubham Sinha , Ming Zhang

We compute the Euler characteristics of quiver Grassmannians and quiver flag varieties of tree and band modules and prove their positivity. This generalizes some results by G.C. Irelli [arXiv:0910.2592]. As an application we consider the…

Representation Theory · Mathematics 2010-02-17 Nicolas Poettering
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