Algebra Seminar

Tuesday, October 16, 2018 2:30 pm - 2:30 pm EDT (GMT -04:00)

Ozgur Esentepe, University of Toronto

"Noncommutative Resolutions and Annihilation of Cohomology"

Classical results in algebraic geometry, commutative algebra and homological algebra due to Zariski, Serre, Auslander and Buchsbaum tell us that R is a regular ring of dimension d if and only if it has global dimension d. If moreover, R is the coordinate ring of a reduced affine variety X, then having finite global dimension is also equivalent to smoothness of X. Hence, when there are singularities, the functor Ext^n(-,-) is nonzero for any positive integer n. We say that a ring element is a cohomology annihilator if it annihilates all large enough Ext groups between any two finitely generated modules. In this talk, we will study cohomology annihilators over Gorenstein rings and relate them to noncommutative (crepant) resolutions.

MC 5403