Resolutions of Richardson varieties, stable curves, and dual simplicial spheres
Allen Knutson (Cornell)
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
Stanford algebraic geometry seminar
Series comments: The seminar was online for a significant period of time, but for now is solely in person. More seminar information (including slides and videos, when available): agstanford.com
Organizer: | Ravi Vakil* |
*contact for this listing |