2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/34042Is there a version of the notions of "state" and "observable" wide enough to apply naturally and in a covariant manner to relativistic systems? I discuss here a tentative answer.7 pages, no figures. Completely revised versionGeneral Relativity and Quantum CosmologyA note on the foundation of relativistic mechanics. I: Relativistic observables and relativistic statestext