3 papers
math.CO2026
Grothendieck positivity for normal square root crystals
Eric Marberg, Kam Hung Tong, Tianyi Yu
Normal crystals (also known as Stembridge crystals) are commonly used to establish the Schur positivity of symmetric functions, as their characters are sums of Schur polynomials. I…
math.CO2025
A positive combinatorial formula for the double Edelman--Greene coefficients
Jack Chen-An Chou, Tianyi Yu
Lam, Lee, and Shimozono introduced the double Stanley symmetric functions in their study of the equivariant geometry of the affine Grassmannian. They proved that the associated dou…
math.CO2024
Tableau formula for vexillary double Edelman--Greene coefficients
Adam Gregory, Zachary Hamaker, Tianyi Yu
Lam, Lee and Shimozono recently introduced backstable double Grothendieck polynomials to represent -theory classes of the infinite flag variety. They used them to define double…