Algebraic Geometry Seminar: Dave Anderson (University of Washington / UBC)

Given a sequence of roots, one can construct a corresponding Bott-Samelson variety. These varieties are basic tools in representation theory and geometry of G/P's; for instance, the Bott-Samelson varieties corresponding to reduced sequences resolve singularities of Schubert varieties. Partly because of these connections, a good understanding of line bundles and divisors, including descriptions of the nef and effective cones, is of interest. In this talk, I'll explain what is known about these questions, what I would like to know, and how much I know of what I'd like to know.