3 papers
math.CO2026
Equivariant Schubert Calculus for Inverse Grassmannian Permutations
Yiming Chen, Neil J. Y. Fan, Rui Xiong +1
We give a Graham-positive expansion for the product of two double Schubert polynomials indexed by two inverse Grassmannian permutations. Surprisingly, the nonzero structure constan…
math.CO2025
Bumpless Pipe Dream Fragments -- Equivariant Geometry of Clans
Yiming Chen, Neil J. Y. Fan, Rui Xiong +1
In this paper, we establish a new geometric setting for bumpless pipe dreams and double Schubert polynomials. Building on the notion of bumpless pipe dream fragments, we define cla…
math.CO2025
Valuative Invariants of Catalan Matroids
Yiming Chen, Yao Li, Ming Yao
We decompose the indicator function of each -Catalan matroid polytope as a weighted sum of indicator function of matroid polytopes that correspond to direct sums of uniform…