2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/162508A 'Liouville structure' is a structure isomorphic to a cotangent vector fibration. A Liouville structure is an essential ingredient of every variational formulation of a physical theory. For reasons of interpretation the Liouville structure can not be replaced by the corresponding cotangent fibration. We give a precise definition of Liouville structures, study their properties, and give examples used in variational formulations of mechanics.Mathematical PhysicsDifferential Geometry53Z05, 53D99, 70H99text