85 citations · 86 across the 2 of their papers we have counts for
6 papers
Revisiting observables in generally covariant theories in the light of gauge fixing methods
J. M. Pons, D. C. Salisbury, K. A. Sundermeyer
We derive for generally covariant theories the generic dependency of observables on the original fields, corresponding to coordinate-dependent gauge fixings. This gauge choice is e…
Peter Bergmann and the invention of constrained Hamiltonian dynamics
D. C. Salisbury
Peter Bergmann was a co-inventor of the algorithm for converting singular Lagrangian models into a constrained Hamiltonian dynamical formalism. This talk focuses on the work of Ber…
The issue of time in generally covariant theories and the Komar-Bergmann approach to observables in general relativity
J. M. Pons, D. C. Salisbury
Diffeomorphism-induced symmetry transformations and time evolution are distinct operations in generally covariant theories formulated in phase space. Time is not frozen. Diffeomorp…
Reparameterization invariants for anisotropic Bianchi I cosmology with a massless scalar source
D. C. Salisbury, J. Helpert, A Schmitz
Intrinsic time-dependent invariants are constructed for classical, flat, homogeneous, anisotropic cosmology with a massless scalar material source. Invariance under the time repara…
Gauge Fixing and Observables in General Relativity
D. C. Salisbury
The conventional group of four-dimensional diffeomorphisms is not realizeable as a canonical transformation group in phase space. Yet there is a larger field-dependent symmetry tra…
Quantum general invariance and loop gravity
Donald C. Salisbury
A quantum physical projector is proposed for generally covariant theories which are derivable from a Lagrangian. The projector is the quantum analogue of the integral over the gene…