Algebraic Geometry Seminar
Title: Counting with quadratic forms
Abstract: We explain, without many technical details, how to give solutions to enumerative geometry problems over fields that are not algebraically closed. The main example we are going to consider are the counts of lines on hypersurfaces, focusing on how to interpret these counts geometrically. If time permits, we will talk about Euler characteristics, how to use them to get a refinement of Donaldson-Thomas invariants and discuss some related open questions. This includes joint work with S. McKean and S. Pauli, joint work with J. Walcher and joint work in progress with R. Azouri.