Seminario del 2021

Febbraio
16
2021
Allen Knutson (Cornell University)
Kogan Schubert calculus from bumpless pipe dreams
nell'ambito della serie: SEMINARIO DI ALGEBRA E GEOMETRIA
algebra e geometria
Kogan gave a combinatorial rule (rediscovered by Lenart and by Assaf) for computing the product of a Schur polynomial S_lambda(x_1..x_k) by a Schubert polynomial S_pi, subject to the condition that pi's last descent is at or before k. Yong and I gave a streamlined proof, using Lascoux' transition formula for Schubert polynomials. As the Lee-Lam-Shimozono bumpless pipe dream formula for Schuberts is tightly compatible with transition (an observation of Weigand's), using them we can give an even tighter formula for Kogan's coefficients.
organizzato da: Jacopo Gandini, Luca Moci, Giovanni Mongardi nell'ambito del progetto TInGeCoRe "The Interplay of Geometry, Combinatorics and Representation Theory" (Bando Strutture 2020)

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