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arXiv · 2506.09421

Graham positivity of triple Schubert calculus

Yibo Gao·Rui Xiong
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Abstract

We prove Samuel's conjecture on certain Graham positivity of the expansion coefficient of two double Schubert polynomials in three sets of variables by establishing a refined version of Graham's positivity theorem. As a corollary, we prove Kirillov's conjecture on the positivity of skew divided difference operators applied to Schubert polynomials.

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Yibo Gao, Rui Xiong. 2025-06-11. Graham positivity of triple Schubert calculus. https://arxiv.org/abs/2506.09421

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