3 papers
math.CO2025
Hybrid pipe dreams for the lower-upper scheme
Allen Knutson, Paul Zinn-Justin
In [KU23] were introduced hybrid pipe dreams interpolating between classic and bumpless pipe dreams, each hybridization giving a different formula for double Schubert polynomials.…
math.AG2025
Stable map quotients (and orbifold log resolutions) of Richardson varieties
Allen Knutson
Let be a Richardson variety in a generalized partial flag manifold. We use equivariant stable map spaces to define a canonical resolution $\w…
math.CO2024
Generic pipe dreams, lower-upper varieties, and Schwartz-MacPherson classes
Allen Knutson, Paul Zinn-Justin
We recall the lower-upper varieties from [Knutson '05] and give a formula for their equivariant cohomology classes, as a sum over generic pipe dreams. We recover as limits the clas…