Ulrich Derenthal, University of Goettingen
Application of universal torsors to Manin's conjecture

In 1989, Manin gave a very general conjecture about the asymptotic behavior of the number of rational points of bounded height on suitable varieties.

The goal of this talk is to explain Manin's conjecture in the case of singular Del Pezzo surfaces of degree 4, and to show how universal torsors can be used to prove it in some cases.