2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/116365In this article we obtain some positive results about the existence of a common nontrivial invariant subspace for $N$-tuples of not necessarily commuting operators on Banach spaces with a Schauder basis. The concept of joint quasinilpotence plays a basic role. Our results complement recent work by Kosiek \cite{6} and Ptak \cite{8}.7 pagesFunctional Analysis47B37; 47B38; 47B99text