Resolutions of Richardson varieties, stable curves, and dual simplicial spheres

Allen Knutson (Cornell)

Fri Jan 28, 20:00-21:00 (5 months ago)

Abstract: The combinatorics of a simple normal crossings divisor determines a "dual" simplicial complex. Kollár and Xu showed that when this divisor is anticanonical, the simplicial complex has the rational homology of a sphere. I'll construct two resolutions-of-singularities of Richardson varieties (a slight generalization of Schubert varieties), one using Bott-Samelson manifolds, the other (requiring no choices!) using circle-equivariant stable curves. In each case the dual simplicial complex is actually homeomorphic to a sphere.

algebraic geometry

Audience: researchers in the topic

( slides | video )


Stanford algebraic geometry seminar

Series comments: This seminar requires both advance registration, and a password. Register at stanford.zoom.us/meeting/register/tJEvcOuprz8vHtbL2_TTgZzr-_UhGvnr1EGv Password: 362880

If you have registered once, you are always registered for the seminar, and can join any future talk using the link you receive by email. If you lose the link, feel free to reregister. This might work too: stanford.zoom.us/j/95272114542

More seminar information (including slides and videos, when available): agstanford.com

Organizer: Ravi Vakil*
*contact for this listing

Export talk to