Double orthodontia formulas and Lascoux positivity

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Setiabrata, Linus, Dizier, Avery St.
Format: Preprint
Veröffentlicht: 2024
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866929535727960064
author Setiabrata, Linus
Dizier, Avery St.
author_facet Setiabrata, Linus
Dizier, Avery St.
contents We give a new formula for double Grothendieck polynomials based on Magyar's orthodontia algorithm for diagrams. Our formula implies a similar formula for double Schubert polynomials $\mathfrak S_w(\mathbf x;\mathbf y)$. We also prove a curious positivity result: for vexillary permutations $w\in S_n$, the polynomial $x_1^n\dots x_n^n \mathfrak S_w(x_n^{-1}, \dots, x_1^{-1}; 1,\dots,1)$ is a graded nonnegative sum of Lascoux polynomials. We conjecture that this positivity result holds for all $w\in S_n$. This conjecture would follow from a problem of independent interest regarding Lascoux positivity of certain products of Lascoux polynomials.
format Preprint
id arxiv_https___arxiv_org_abs_2410_08038
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Double orthodontia formulas and Lascoux positivity
Setiabrata, Linus
Dizier, Avery St.
Combinatorics
We give a new formula for double Grothendieck polynomials based on Magyar's orthodontia algorithm for diagrams. Our formula implies a similar formula for double Schubert polynomials $\mathfrak S_w(\mathbf x;\mathbf y)$. We also prove a curious positivity result: for vexillary permutations $w\in S_n$, the polynomial $x_1^n\dots x_n^n \mathfrak S_w(x_n^{-1}, \dots, x_1^{-1}; 1,\dots,1)$ is a graded nonnegative sum of Lascoux polynomials. We conjecture that this positivity result holds for all $w\in S_n$. This conjecture would follow from a problem of independent interest regarding Lascoux positivity of certain products of Lascoux polynomials.
title Double orthodontia formulas and Lascoux positivity
topic Combinatorics
url https://arxiv.org/abs/2410.08038