caa a22 4500 467887918 CHVBK 20180406152740.0 cr unu---uuuuu 170328e20060201xx s 000 0 eng 10.1007/s10714-005-0217-6 doi (NATIONALLICENCE)springer-10.1007/s10714-005-0217-6 The physical role of gravitational and gauge degrees of freedom in general relativity — I: Dynamical synchronization and generalized inertial effects [Elektronische Daten] [Luca Lusanna, Massimo Pauri] This is the first of a couple of papers in which the peculiar capabilities of the Hamiltonian approach to general relativity are exploited to get both new results concerning specific technical issues, and new insights about old foundational problems of the theory. The first paper includes: (1) a critical analysis of the various concepts of symmetry related to the Einstein-Hilbert Lagrangian viewpoint on the one hand, and to the Hamiltonian viewpoint, on the other. This analysis leads, in particular, to a re-interpretation of active diffeomorphisms as passive and metric-dependent dynamical symmetries of Einstein's equations, a re-interpretation which enables to disclose the (not widely known)) connection of a subgroup of them to Hamiltonian gauge transformations on-shell; (2) a re-visitation of the canonical reduction of the ADM formulation of general relativity, with particular emphasis on the geometro-dynamical effects of the gauge-fixing procedure, which amounts to the definition of a global non-inertial, space-time laboratory. This analysis discloses the peculiar dynamical nature that the traditional definition of distant simultaneity and clock-synchronization assume in general relativity, as well as the gauge relatedness of the "conventions” which generalize the classical Einstein's convention. (3) a clarification of the physical role of Dirac and gauge variables, as their being related to tidal-like and generalized inertial effects, respectively. This clarification is mainly due to the fact that, unlike the standard formulations of the equivalence principle, the Hamiltonian formalism allows to define a generalized notion of "force” in general relativity in a natural way. Springer-Verlag, 2005 Canonical gravity nationallicence Gauge variables and inertial effects nationallicence Dirac observables and tidal effects nationallicence General covariance vs. dynamical symmetries nationallicence Lusanna Luca Sezione INFN di Firenze, Polo Scientifico, Via Sansone 1, 50019, Sesto Fiorentino (FI), Italy aut Pauri Massimo Dipartimento di Fisica - Sezione Teorica, Universita' di Parma, Parco Area Scienze 7/A, 43100, Parma, Italy aut General Relativity and Gravitation Springer US; http://www.springer-ny.com 38/2(2006-02-01), 187-227 0001-7701 38:2<187 2006 38 10714 https://doi.org/10.1007/s10714-005-0217-6 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10714-005-0217-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Lusanna Luca Sezione INFN di Firenze, Polo Scientifico, Via Sansone 1, 50019, Sesto Fiorentino (FI), Italy aut NATIONALLICENCE 700 1- Pauri Massimo Dipartimento di Fisica - Sezione Teorica, Universita' di Parma, Parco Area Scienze 7/A, 43100, Parma, Italy aut NATIONALLICENCE 773 0- General Relativity and Gravitation Springer US; http://www.springer-ny.com 38/2(2006-02-01), 187-227 0001-7701 38:2<187 2006 38 10714 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer