2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/228677We introduce three nested Lie algebras of infinitesimal `isometries' of a Galilei space-time structure which play the rôle of the algebra of Killing vector fields of a relativistic Lorentz space-time. Non trivial extensions of these Lie algebras arise naturally from the consideration of Newton-Cartan-Bargmann automorphisms.Plain TeX, 8 pagesMathematical PhysicsGeneral Relativity and Quantum CosmologyHigh Energy Physics - Theorytext