1994/09/30 by S. C. Beluardi, Rafael Ferraro · 1 citation
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Noncommutative and Quantum Gravity Theories #gr-qc
paper · pdf · doi:10.1103/physrevd.52.1963
published as Phys.Rev. D52 (1995) 1963-1969 · 14 pages (TeX manuscript). Revised and enlarged version
arxiv created 1995/04/26 · openalex publication_date 1995/08/15 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Extrinsic time is identified in most isotropic and homogeneous cosmological models by matching it with the ideal clock---a parametrized system whose only ``degree of freedom'' is time. Once this matching is established, the cosmological models are quantized in the same way as the ideal clock. The space of solutions of the Wheeler-DeWitt equation is turned into a Hilbert space by inserting a time-dependent operator in the inner product, yielding a unitary theory equivalent to the phase-space-reduced theory.