2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/69165We study a skew product with a curve of neutral points. We show that there exists a unique absolutely continuous invariant probability measure, and that the Birkhoff averages of a sufficiently smooth observable converge to a normal law or a stable law, depending on the average of the observable along the neutral curve.32 pagesDynamical Systems37A50; 37C40; 60F05text