Fluid Entropy as Time-Variable in Canonical Quantum Gravity
arXiv:0904.0521
Abstract
The Brown-Kuchař mechanism is applied in the case of General Relativity coupled with the Schutz' model for a perfect fluid. Using the canonical formalism and manipulating the set of modified constraints one is able to recover the definition of a time evolution operator, i.e. a physical Hamiltonian, expressed as a functional of gravitational variables and the entropy.
5 pages, Proceedings of The 3rd Stueckelberg Workshop on Relativistic Field Theories