Regular Article - Theoretical Physics
Pre-inflation from the multiverse: can it solve the quadrupole problem in the cosmic microwave background?
Department of Theoretical Physics, University of the Basque Country UPV/EHU, P.O. Box 644, 48080, Bilbao, Spain
2 IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Spain
3 Institute of Physics, University of Szczecin, Wielkopolska 15, 70-451, Szczecin, Poland
4 Instituto de Física Fundamental, CSIC, Serrano 121, 28006, Madrid, Spain
5 Estación Ecológica de Biocosmología, Pedro de Alvarado 14, 06411, Medellín, Spain
* e-mail: email@example.com
Accepted: 4 March 2018
Published online: 21 March 2018
We analyze a quantized toy model of a universe undergoing eternal inflation using a quantum-field-theoretical formulation of the Wheeler–DeWitt equation. This so-called third quantization method leads to the picture that the eternally inflating universe is converted to a multiverse in which sub-universes are created and exhibit a distinctive phase in their evolution before reaching an asymptotic de Sitter phase. From the perspective of one of these sub-universes, we can thus analyze the pre-inflationary phase that arises naturally. Assuming that our observable universe is represented by one of those sub-universes, we calculate how this pre-inflationary phase influences the power spectrum of the cosmic microwave background (CMB) anisotropies and analyze whether it can explain the observed discrepancy of the power spectrum on large scales, i.e. the quadrupole issue in the CMB. While the answer to this question is negative in the specific model analyzed here, we point out a possible resolution of this issue.
© The Author(s), 2018