Sergey Finashin: Strong invariants of real del Pezzo surfaces via signed count of rational curves

Date: 2023-06-29

Time: 11:00 - 12:00


Sergey Finashin, Middle East Technical University


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.