Next Article in Journal
Studying Cosmic Ray Sources Using Intergalactic Electromagnetic Cascades
Next Article in Special Issue
Classical and Quantum f(R) Cosmology: The Big Rip, the Little Rip and the Little Sibling of the Big Rip
Previous Article in Journal
Strongly Continuous Representations in the Hilbert Space: A Far-Reaching Concept
Previous Article in Special Issue
Cosmological Particle Production in Quantum Gravity
Review

Quantum and Classical Cosmology in the Brans–Dicke Theory

1
Núcleo Cosmo-ufes & Departamento de Física, Universidade Federal do Espírito Santo, Vitória 29075-910, ES, Brazil
2
National Research Nuclear University MEPhI, Kashirskoe sh. 31, 115409 Moscow, Russia
*
Author to whom correspondence should be addressed.
Academic Editor: Jaime Haro Cases
Universe 2021, 7(8), 286; https://doi.org/10.3390/universe7080286
Received: 28 June 2021 / Revised: 29 July 2021 / Accepted: 2 August 2021 / Published: 5 August 2021
(This article belongs to the Special Issue Quantum Cosmology)
In this paper, we discuss classical and quantum aspects of cosmological models in the Brans–Dicke theory. First, we review cosmological bounce solutions in the Brans–Dicke theory that obeys energy conditions (without ghost) for a universe filled with radiative fluid. Then, we quantize this classical model in a canonical way, establishing the corresponding Wheeler–DeWitt equation in the minisuperspace, and analyze the quantum solutions. When the energy conditions are violated, corresponding to the case ω<32, the energy is bounded from below and singularity-free solutions are found. However, in the case ω>32, we cannot compute the evolution of the scale factor by evaluating the expectation values because the wave function is not finite (energy spectrum is not bounded from below). However, we can analyze this case using Bohmian mechanics and the de Broglie–Bohm interpretation of quantum mechanics. Using this approach, the classical and quantum results can be compared for any value of ω. View Full-Text
Keywords: Brans–Dicke theory; bounce models; de Broglie–Bohm interpretation Brans–Dicke theory; bounce models; de Broglie–Bohm interpretation
Show Figures

Figure 1

MDPI and ACS Style

Almeida, C.R.; Galkina, O.; Fabris, J.C. Quantum and Classical Cosmology in the Brans–Dicke Theory. Universe 2021, 7, 286. https://doi.org/10.3390/universe7080286

AMA Style

Almeida CR, Galkina O, Fabris JC. Quantum and Classical Cosmology in the Brans–Dicke Theory. Universe. 2021; 7(8):286. https://doi.org/10.3390/universe7080286

Chicago/Turabian Style

Almeida, Carla R., Olesya Galkina, and Julio C. Fabris 2021. "Quantum and Classical Cosmology in the Brans–Dicke Theory" Universe 7, no. 8: 286. https://doi.org/10.3390/universe7080286

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop