2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/143422Given a diffeomorphism of the plane, which has a periodic orbit, we show how Nielsen fixed point theory can be used to establish the existence of a fixed point which is linked with this periodic orbit.in French, 4 pagesDynamical Systems55M20; 57N05; 58C30; 58F20text