Extrinsic time in quantum cosmology

SANTIAGO BELUARDI; RAFAEL FERRARO

PHYSICAL REVIEW D - PARTICLE AND FILDS

The American Physical Society

Año: 1995 vol. 52 p. 1963 - 1969

0556-2821

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 tghe 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.