6 papers
Non-vanishing of Single, Double, and Triple Schubert Structure Constants
Yiming Chen, Neil J. Y. Fan, Rui Xiong +1
The Schubert vanishing problem asks whether the single Schubert coefficients are zero. In this paper, we consider the non-vanishing problems of double Schubert coeffici…
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…
Lattice-free Schubitopes
Jinren Dou, Neil J. Y. Fan, Kunwen Liu
In this paper, we provide a simple criterion for the Schubitope associated to a diagram to be lattice-free. We further show that is lattice-…
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…
Chern Classes of Open Projected Richardson Varieties and of Affine Schubert Cells
Neil J. Y. Fan, Peter L. Guo, Changjian Su +1
The open projected Richardson varieties form a stratification for the partial flag variety . We compare the Segre--MacPherson classes of open projected Richardson varieties wi…
Zero-one Grothendieck Polynomials
Yiming Chen, Neil J. Y. Fan, Zelin Ye
Fink, Mészáros and St.Dizier showed that the Schubert polynomial is zero-one if and only if avoids twelve permutation patterns. In this paper, we prove that…