On smoothness and Gorensteinness of Schubert varieties -- Alexander Yong
We give an explicit combinatorial characterization of which Schubert varieties in the flag variety are smooth; geometrically: a Schubert variety is Gorenstein if and only if it is Gorenstein at the generic points of the singular locus. We also describe the canonical sheaf in terms of the Borel-Weil construction. I'll also explain applications of this to geometric and representation-theoretic questions.