Blown-up toric surfaces with non-polyhedral effective cone and applications to moduli spaces

Speaker

Ana-Maria Castravet

Abstract

I will discuss recent joint work with Antonio Laface, Jenia Tevelev and Luca Ugaglia, in which we construct examples of projective toric surfaces whose blow-up at a general point has a
non-polyhedral (i.e., not finitely generated) cone of effective divisors, both in characteristic 0 and in prime characteristic. As a consequence, the Grothendieck-Knudsen moduli space of stable rational curves with n>=10 markings has a non polyhedral cone of effective divisors.