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Related papers: On cyclic Schur-positive sets of permutation

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This is a short note about Schur positivity. We introduce Schur polynomials and explain how they appear in the representation theory of the general linear group. We end with a new result of the author with F. Bergeron and V. Reiner that…

Combinatorics · Mathematics 2018-09-13 Rebecca Patrias

For integers $a_1, \dots, a_n \ge 0$ and $k \ge 1$, let $\mathcal L_{k+2}(a_1, \dots, a_n)$ denote the set of permutations of $\{1, \dots, a_1+\dots+a_n\}$ whose descent set is contained in $\{a_1, a_1+a_2, \dots, a_1+\dots+a_{n-1}\}$, and…

Combinatorics · Mathematics 2023-10-03 Evan Chen

Chen proposed a conjecture on the log-concavity of the generating function for the symmetric group with respect to the length of longest increasing subsequences of permutations. Motivated by Chen's log-concavity conjecture, B\'{o}na,…

Combinatorics · Mathematics 2017-03-21 Alice L. L. Gao , Matthew H. Y. Xie , Arthur L. B. Yang

In previous work of this author it was conjectured that the sum of power sums $p_\lambda,$ for partitions $\lambda$ ranging over an interval $[(1^n), \mu]$ in reverse lexicographic order, is Schur-positive. Here we investigate this…

Combinatorics · Mathematics 2025-09-09 Sheila Sundaram

Let $X$ be a smooth projective variety of dimension $n$, and let $E$ be an ample vector bundle over $X$. We show that any non-zero Schur class of $E$, lying in the cohomology group of bidegree $(n-1, n-1)$, has a representative which is…

Algebraic Geometry · Mathematics 2020-07-27 Jian Xiao

We define and study odd analogues of classical geometric and combinatorial objects associated to permutations, namely odd Schubert varieties, odd diagrams, and odd inversion sets. We show that there is a bijection between odd inversion sets…

Combinatorics · Mathematics 2020-06-24 Francesco Brenti , Angela Carnevale

We prove an identity conjectured by Adin and Roichman involving the descent set of $\lambda$-unimodal cyclic permutations. These permutations appear in formulas for characters of certain representations of the symmetric group. Such formulas…

Combinatorics · Mathematics 2016-06-07 Kassie Archer

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

We introduce a new paradigm for proving the Schur $P$-positivity. Generalizing dual equivalence, we give an axiomatic definition for a family of involutions on a set of objects to be a queer dual equivalence, and we prove whenever such a…

Combinatorics · Mathematics 2021-03-10 Sami H. Assaf

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

Using a result of Gessel and Reutenauer, we find a simple formula for the number of cyclic permutations with a given descent set, by expressing it in terms of ordinary descent numbers (i.e., those counting all permutations with a given…

Combinatorics · Mathematics 2019-07-16 Sergi Elizalde , Justin M. Troyka

In 2010, B. Rhoades proved that promotion together with the fake-degree polynomial associated with rectangular standard Young tableaux give an instance of the cyclic sieving phenomenon. We extend this result to all skew standard Young…

Combinatorics · Mathematics 2023-10-04 Per Alexandersson , Stephan Pfannerer , Martin Rubey , Joakim Uhlin

The notion of shuffle-compatible permutation statistics was implicit in Stanley's work on P-partitions and was first explicitly studied by Gessel and Zhuang. The aim of this paper is to prove that the triple ${\rm (udr, pk, des)}$ is…

Combinatorics · Mathematics 2022-05-12 Lihong Yang , Sherry H. F. Yan

Let $m, n$ be positive integers such that $m>1$ divides $n$. In this paper, we introduce a special class of piecewise-affine permutations of the finite set $[1, n]:=\{1, \ldots, n\}$ with the property that the reduction $\pmod m$ of $m$…

Number Theory · Mathematics 2020-03-13 Lucas Reis , Sávio Ribas

Any permutation has a disjoint cycle decomposition and concept generates an equivalence class on the symmetry group called the cycle-type. The main focus of this work is on permutations of restricted cycle-types, with particular emphasis on…

Combinatorics · Mathematics 2014-06-11 Tewodros Amdeberhan , Victor H. Moll

A permutation is defined to be cycle-up-down if it is a product of cycles that, when written starting with their smallest element, have an up-down pattern. We prove bijectively and analytically that these permutations are enumerated by the…

Combinatorics · Mathematics 2009-09-30 Emeric Deutsch , Sergi Elizalde

In this paper we study the cycle descent statistic on permutations. Several involutions on permutations and derangements are constructed. Moreover, we construct a bijection between negative cycle descent permutations and Callan perfect…

Combinatorics · Mathematics 2015-12-08 Jun Ma , Shimei Ma , Yeong-Nan Yeh , Zhu Xu

The quasisymmetric generating function of the set of permutations whose inverses have a fixed descent set is known to be symmetric and Schur-positive. The corresponding representation of the symmetric group is called the descent…

Combinatorics · Mathematics 2023-09-26 Vassilis Dionyssis Moustakas

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

The product $s_\mu s_\nu$ of two Schur functions is one of the most famous examples of a Schur-positive function, i.e. a symmetric function which, when written as a linear combination of Schur functions, has all positive coefficients. We…

Combinatorics · Mathematics 2007-05-23 Francois Bergeron , Peter McNamara