2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/66565We characterize co-Hopfian finitely generated torsion free nilpotent groups in terms of their Lie algebra automorphisms, and construct many examples of such groups.8 pages, to appear in Bull. London Math. SocGroup TheoryGeometric Topology17B30; 20F18text