par Henneaux, Marc ;Kleinschmidt, Axel ;Gómez, Gustavo Lucena
Référence Annals of the University of Craiova, Physics, 21, 1 SPEC. ISSUE, page (1-10)
Publication Publié, 2011
Article révisé par les pairs
Résumé : Gauge symmetries lead to first-class constraints. This assertion is of course true only for non trivial gauge symmetries, i.e., gauge symmetries that act non trivially on-shell on the dynamical variables. We illustrate this well-appreciated fact for time reparametrization invariance in the context of modifications of gravity - suggested in a recent proposal by Hořava - in which the Hamiltonian constraint is deformed by arbitrary spatial diffeomorphism invariant terms, where some subtleties are found to arise.