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Zero-one dual characters of flagged Weyl modules

Published online by Cambridge University Press:  08 July 2025

Peter L. Guo*
Affiliation:
Center for Combinatorics, Nankai University , LPMC, Tianjin 300071, P.R. China
Zhuowei Lin
Affiliation:
Center for Combinatorics, Nankai University , LPMC, Tianjin 300071, P.R. China e-mail: zwlin0825@163.com
Simon C. Y. Peng
Affiliation:
Center for Applied Mathematics, Tianjin University, Tianjin 300072, P.R. China e-mail: pcy@tju.edu.cn

Abstract

We prove a criterion of when the dual character $\chi _{D}(x)$ of the flagged Weyl module associated a diagram D in the grid $[n]\times [n]$ is zero-one, that is, the coefficients of monomials in $\chi _{D}(x)$ are either 0 or 1. This settles a conjecture proposed by Mészáros–St. Dizier–Tanjaya. Since Schubert polynomials and key polynomials occur as special cases of dual flagged Weyl characters, our approach provides a new and unified proof of known criteria for zero-one Schubert/key polynomials due to Fink–Mészáros–St. Dizier and Hodges–Yong, respectively.

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© The Author(s), 2025. Published by Cambridge University Press on behalf of Canadian Mathematical Society

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