# Quantum and Classical Cosmology in the Brans–Dicke Theory

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## Abstract

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## 1. Introduction

## 2. A Short Review of the Brans–Dicke Theory

## 3. Bouncing Solutions and the Energy Conditions

## 4. Canonical Quantization of the BD Theory

## 5. Analysis of the Solution via the de Broglie–Bohm Approach

#### 5.1. The Scalar Field Is Absent

#### 5.2. A Single Scalar Mode

#### 5.3. Multiple Scalar Modes

## 6. Conclusions

## Author Contributions

## Funding

## Conflicts of Interest

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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 César Fabris. 2021. "Quantum and Classical Cosmology in the Brans–Dicke Theory" *Universe* 7, no. 8: 286.
https://doi.org/10.3390/universe7080286