Parametrizing fluids in canonical quantum gravity

Abstract

The problem of time is an unsolved issue of canonical General Relativity. A possible solution is the Brown-Kuchar mechanism which couples matter to the gravitational field and recovers a physical, i.e. non vanishing, observable Hamiltonian functional by manipulating the set of constraints. Two cases are analyzed. A generalized scalar fluid model provides an evolutionary picture, but only in a singular case. The Schutz' model provides an interesting singularity free result: the entropy per baryon enters the definition of the physical Hamiltonian. Moreover in the co-moving frame one is able to identify the time variable tau with the logarithm of entropy.

5 pages, no figures. Proceeding of the II Stueckelberg Workshop, Pescara, Sept. 2007

References in corpus (2)

• Dust as a Standard of Space and Time in Canonical Quantum Gravity
• Solving the Problem of Time in General Relativity and Cosmology with Phantoms and k -- Essence

Cited by in corpus (4)

• WKB Approaches to Restore Time in Quantum Cosmology: Predictions and Shortcomings
• Quantum gravity corrections to the matter dynamics in the presence of a reference fluid
• QFT in Curved Spacetime from Quantum Gravity: proper WKB decomposition of the gravitational component
• Time evolution in quantum cosmology