Weekly seminar of AG Laboratory: Paul Zinn-Justin

Paul Zinn-Justin (Melbourne)  with the talk  Schubert calculus and quantum integrability

We formulate new combinatorial (puzzle) rules for Schubert calculus in the d-step flag variety, d<=4. More precisely, generalizing my previous work for d=1, we show how to define an integrable model that computes the structure constants of the (equivariant) cohomology (or K-theory) of the d-step flag variety in the basis of Schubert classes. Deligne's exceptional series appears naturally. We also explain the connection to Maulik-Okounkov stable classes. This is joint work with A. Knutson.