In:
International Journal of Modern Physics D, World Scientific Pub Co Pte Ltd, Vol. 28, No. 06 ( 2019-04), p. 1950073-
Abstract:
We compare two different approaches to the treatment of the Wheeler–DeWitt (WDW) equation and the introduction of time in quantum cosmology. One approach is based on the gauge-fixing procedure in theories with first-class constraints and the construction of the corresponding Hilbert space of quantum states. The other approach uses the Born–Oppenheimer (BO) method, based on the existence of two energy scales in the model under consideration. We apply both to a very simple cosmological model, including a massless scalar field filling a flat Friedmann universe, and observe that they give similar predictions. We also discuss the problem of time in nonrelativistic quantum mechanics and some questions concerning the correspondence between classical and quantum theories.
Type of Medium:
Online Resource
ISSN:
0218-2718
,
1793-6594
DOI:
10.1142/S0218271819500731
Language:
English
Publisher:
World Scientific Pub Co Pte Ltd
Publication Date:
2019
SSG:
16,12
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