Speaker
Sergey Finashin, Middle East Technical University
Abstract
The initial example motivating our research (joint with V.Kharlamov) is a signed count of real lines on real cubic surfaces, which gives 3, independently of the choice of its real structure: in that sense such count gives a “strong invariant”.
We defined and calculated similar invariants as a certain signed count of rational curves involving a combinations of all Welschinger numbers in a given anticanonical degree for del Pezzo surfaces of degrees 1,2 and 3.