EVENT DETAILS AND ABSTRACT

Title: The Noether-Lefschetz theorem in arbitrary characteristic
Speaker: Lena Ji
Speaker Info: University of Michigan
Brief Description: Zoom talk
Special Note:
Abstract:

The classical Noether-Lefschetz theorem says that for a very general surface S of degree 4 in P^3 over the complex numbers, the restriction map from the divisor class group on P^3 to S is an isomorphism. In this talk, we will show a Noether-Lefschetz result for varieties over fields of arbitrary characteristic. The proof uses the relative Jacobian of a curve fibration, and it also works for singular varieties (for Weil divisors).