SMS scnews item created by Catherine Meister at Tue 26 May 2026 0926
Type: Seminar
Modified: Thu 28 May 2026 1340; Thu 28 May 2026 1503
Distribution: World
Expiry: 23 Jun 2026
Calendar1: 11 Jun 2026 1300-1400
CalLoc1: SMRI Seminar Room (A12 Macleay Room 301)
CalTitle1: Schubert calculus via puzzles
Auth: cmeister@ac02gr132pn7c.shared.sydney.edu.au (cmei0631) in SMS-SAML

SMRI Seminar: Knutson

Schubert calculus via puzzles

Allen Knutson, Cornell University

SMRI Seminar, Thursday 11th June 2026, 1 pm – 2 pm, SMRI Seminar Room (A12 Macleay Room 301)

Abstract: "Littlewood-Richardson numbers" come up in many places: the representation theory of the symmetric group and general linear groups, spectral problems involving Hermitian matrices, and intersection theory on the Grassmannian. The last problem admits many independent (and combinable) generalizations, all of which have formulæ for the intersection numbers, but only a few of which have manifestly positive formulæ. I'll discuss the "puzzle" formalism for most of the sharpest positive formulae, due to me and Terry Tao and further developed with Paul Zinn-Justin. Time permitting, I'll connect the rule to geometric representation theory of quantized loop algebras.

For seminar updates, see our What's On Calendar. Please join us after the seminar for the SMRI afternoon tea, every Thursday at 2 pm on the SMRI Terrace.