Sergio Da Silva

Ph.D. (2018) Cornell University

First Position

Pacific Institute for the Mathematical Sciences (PIMS) postdoctoral fellowship, University of Manitoba

Dissertation

On the Gorensteinization of Schubert varieties via boundary divisors

Advisor

Research Area

Algebraic geometry and algebraic combinatorics

Abstract

We will describe a one-step “Gorensteinization” process for a Schubert variety by blowing-up along its boundary divisor. The local question involves Kazhdan-Lusztig varieties which can be degenerated to affine toric schemes defined using the Stanley-Reisner ideal of a subword complex. The blow-up along the boundary in this toric case is in fact Gorenstein. We show that there exists a degeneration of the blow-up of the Kazhdan-Lusztig variety to this Gorenstein scheme, allowing us to extend this result to Schubert varieties in general. The potential use of this one-step Gorensteinization to describe the non-Gorenstein locus of Schubert varieties is discussed, as well as the relationship between Gorensteinizations and the convergence of the Nash blow-up process in the toric case.