2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/155908The Welschinger invariants of real rational algebraic surfaces are natural analogues of the genus zero Gromov-Witten invariants. We establish a tropical formula to calculate the Welschinger invariants of real toric Del Pezzo surfaces for any conjugation-invariant configuration of points. The formula expresses the Welschinger invariants via the total multiplicity of certain tropical curves (non-Archimedean amoebas) passing through generic configurations of points, and then via the total multiplicity of some lattice path in the convex lattice polygon associated with a given surface. We also present the results of computation of Welschinger invariants, obtained jointly with I. Itenberg and V. Kharlamov.38 pages, 3 figures, misprints (which appeared in the published version) in the formulation of the main theorem are corrected as well as in formula (2.12) for the weight of a tropical curve (thanks to a remark by E. Brugalle)Algebraic GeometryCombinatorics14H15, 12J25, 14H20, 14M25, 14N10text