On Higher Genus Welschinger Invariants of del Pezzo Surfaces

The Welschinger invariants of real rational algebraic surfaces count real rational curves that represent a given divisor class and pass through a generic conjugation-invariant configuration of points. No invariants counting real curves of positive genera are known in general. We indicate particular situations, when Welschinger-type invariants counting real curves of positive genera can be defined. We also prove the positivity and give asymptotic estimates for such Welschinger-type invariants for several del Pezzo surfaces of degree >= 2 and suitable real nef and big divisor classes. In particular, this yields the existence of real curves of given genus and of given divisor class passing through any appropriate configuration of real points on the given surface.