报告人:余讯 (天津大学)

时间: 2021年9月 9日 上午 9:00-10:00

腾讯会议: 641539631

Abstract: Hassett divisors (i.e., the moduli spaces of special cubic fourfolds introduced by Hassett) have played fundamental roles in many studies of cubic fourfolds. In this talk, we extend the non-emptyness and irreducibility of Hassett divisors to the moduli spaces of M-polarizable cubic fourfolds for higher rank lattices M, and show that Fermat cubic fourfold is contained in every Hassett divisor. As applications, we obtain an algorithm to determine the irreducible components of the intersection of any two Hassett divisors and give new examples of rational cubic fourfolds. Moreover, we derive a numerical criterion for the algebraic cohomology of a cubic fourfold having an associated K3 surface. This is based on a joint work with Song Yang.

邀请人：龚成