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.