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By considering type B analogs of permutations and tableaux, we extend abstract dual equivalence to type B in two directions. In one direction, we define involutions on signed permutations and shifted tableaux that give a weak dual…

Combinatorics · Mathematics 2020-03-05 Sami Assaf

The periodic (ordinal) patterns of a map are the permutations realized by the relative order of the points in its periodic orbits. We give a combinatorial characterization of the periodic patterns of an arbitrary signed shift, in terms of…

Combinatorics · Mathematics 2013-05-01 Kassie Archer , Sergi Elizalde

Cylindric Schur functions are a family of symmetric functions that generalize skew Schur functions. We give a short proof that skew cylindric Schur functions expand positively in terms of non-skew cylindric Schur functions. In particular,…

Combinatorics · Mathematics 2026-05-21 Alexander Dobner

We consider the skew diagram $\Delta_n$, which is the $180^\circ$ rotation of the staircase diagram $\delta_n = (n,n-1,n-2,...,2,1)$. We create a staircase with bad foundation by augmenting $\Delta_n$ with another skew diagram, which we…

Combinatorics · Mathematics 2010-03-09 Matthew Morin

A matrix is totally positive if all of its minors are positive. This notion of positivity coincides with the type A version of Lusztig's more general total positivity in reductive real-split algebraic groups. Since skew-symmetric matrices…

Combinatorics · Mathematics 2024-12-24 Jonathan Boretsky , Veronica Calvo Cortes , Yassine El Maazouz

The jeu de taquin process produced a standard Young tableau from a skew standard Young tableau by shifting its entries to the northwest. We generalize this process to posets: certain partial numberings of any poset are shifted upward. A…

Combinatorics · Mathematics 2023-08-04 Robert A. Proctor

We study Schur Q-polynomials evaluated on a geometric progression, or equivalently q-enumeration of marked shifted tableaux, seeking explicit formulas that remain regular at q=1. We obtain several such expressions as multiple basic…

Combinatorics · Mathematics 2008-04-08 Hjalmar Rosengren

We introduce circulant matrices that capture the structure of a skew-polynomial ring F[x;\theta] modulo the left ideal generated by a polynomial of the type x^n-a. This allows us to develop an approach to skew-constacyclic codes based on…

Information Theory · Computer Science 2014-09-30 Neville Fogarty , Heide Gluesing-Luerssen

Determining if a symmetric function is Schur-positive is a prevalent and, in general, a notoriously difficult problem. In this paper we study the Schur-positivity of a family of symmetric functions. Given a partition \lambda, we denote by…

Combinatorics · Mathematics 2013-10-11 Cristina Ballantine , Rosa Orellana

We give a backward jeu de taquin slide analogue on semistandard reverse composition tableaux. These tableaux were first studied by Haglund, Luoto, Mason and van Willigenburg when defining quasisymmetric Schur functions. Our algorithm for…

Combinatorics · Mathematics 2014-10-14 Vasu V. Tewari

We give new product formulas for the number of standard Young tableaux of certain skew shapes and for the principal evaluation of the certain Schubert polynomials. These are proved by utilizing symmetries for evaluations of factorial Schur…

Combinatorics · Mathematics 2020-06-03 Alejandro H. Morales , Igor Pak , Greta Panova

In a recent paper, Ayyer and Behrend present for a wide class of partitions factorizations of Schur polynomials with an even number of variables where half of the variables are the reciprocals of the others into symplectic and/or orthogonal…

Combinatorics · Mathematics 2020-03-31 Arvind Ayyer , Ilse Fischer

We introduce inversions tableaux, a new combinatorial model for Schubert polynomials and Stanley symmetric functions that directly specializes to semi-standard Young tableaux in the Grassmannian case. They are a modification of the balanced…

Combinatorics · Mathematics 2025-07-17 Ilani Axelrod-Freed

We give a combinatorial proof that the product of a Schubert polynomial by a Schur polynomial is a nonnegative sum of Schubert polynomials. Our proof uses Assaf's theory of dual equivalence to show that a quasisymmetric function of Bergeron…

Combinatorics · Mathematics 2014-05-13 Sami Assaf , Nantel Bergeron , Frank Sottile

Fix an integer $t \geq 2$ and a primitive $t^{\text{th}}$ root of unity $\omega$. We consider the specialized skew hook Schur polynomial $\text{hs}_{\lambda/\mu}(X,\omega X,\dots,\omega^{t-1}X/Y,\omega Y,\dots,\omega^{t-1}Y)$, where…

Combinatorics · Mathematics 2025-12-19 Nishu Kumari

We introduce a new operation on skew diagrams called composition of transpositions, and use it and a Jacobi-Trudi style formula to derive equalities on skew Schur Q-functions whose indexing shifted skew diagram is an ordinary skew diagram.…

Combinatorics · Mathematics 2009-09-01 Farzin Barekat , Stephanie van Willigenburg

The circular descent of a permutation $\sigma$ is a set $\{\sigma(i)\mid \sigma(i)>\sigma(i+1)\}$. In this paper, we focus on the enumerations of permutations by the circular descent set. Let $cdes_n(S)$ be the number of permutations of…

Combinatorics · Mathematics 2008-06-05 Hungyung Chang , Jun Ma , Yeong-Nan Yeh

We show that the Skolem Problem is decidable in finitely generated commutative rings of positive characteristic. More precisely, we show that there exists an algorithm which, given a finite presentation of a (unitary) commutative ring…

Logic in Computer Science · Computer Science 2026-03-12 Ruiwen Dong , Doron Shafrir

Given a lower-triangular matrix of real numbers, one can ask the following four total-positivity questions: total positivity of the triangle itself; total positivity of its row-reversal; Toeplitz-total positivity of its row sequences…

Combinatorics · Mathematics 2025-07-28 Bishal Deb , Alan D. Sokal

In this paper a variety of issues are discussed, Schur ring, $S$-sets, circulant orbits, decimation operator and Hadamard matrices and their relation between them is shown. Firstly we define the complete $S$-sets. Next, we study the…

Combinatorics · Mathematics 2019-04-12 Ronald Orozco López