Speaker: Angela Gibney (Georgia)

Title: Conformal Blocks Divisors on \overline{M}_{0,n} from sl_2 and sl_n

Abstract: Given a simple Lie algebra \mathfrak{g}, a positive integer \ell called the level, and an appropriately chosen n-tuple of dominant integral weights lambda of level \ell, one can define a vector bundle on the stacks \overline{M}_{g,n} whose fibers are the so-called vector spaces of conformal blocks. On \overline{M}_{0,n}, first Chern classes of these vector bundles turn out to be semi-ample divisors, and so define morphisms. In this talk I will discuss the simplest examples of these divisors, and show that they can be treated entirely combinatorially. I'll show that every morphism we know of on \overline{M}_{0,n} comes from one of these divisors and even some that we didn't.