Real Enumerative Invariants Relative to the Anti-Canonical Divisor and their Refinement

Abstract

We introduce new invariants of the projective plane (and, more generally, of certain toric surfaces) that arise from the appropriate enumeration of real elliptic curves. These invariants admit a refinement (according to the quantum index) similar to the one introduced by Grigory Mikhalkin in the rational case. We also construct tropical counterparts of the refined elliptic invariants under consideration and establish a tropical algorithm allowing one to compute, via a suitable version of the correspondence theorem, the above invariants.