A plausible model of inflation driven by strong gravitational wave turbulence


It is widely accepted that the primordial universe experienced a brief period of accelerated expansion called inflation. This scenario provides a plausible solution to the horizon and flatness problems. However, the particle physics mechanism responsible for inflation remains speculative with, in particular, the assumption of a scalar field called inflaton. Furthermore, the comparison with the most recent data raises new questions that encourage the consideration of alternative hypotheses. Here, we propose a completely different scenario based on a mechanism whose origins lie in the nonlinearities of the Einstein field equations. We use the analytical results of weak gravitational wave turbulence to develop a phenomenological theory of strong gravitational wave turbulence where the inverse cascade of wave action plays a key role. In this scenario, the space-time metric excitation triggers an explosive inverse cascade followed by the formation of a condensate in Fourier space whose growth is interpreted as an expansion of the universe. Contrary to the idea that gravitation can only produce a decelerating expansion, our study reveals that strong gravitational wave turbulence could be a source of inflation. The fossil spectrum that emerges from this scenario is shown to be in agreement with the cosmic microwave background radiation measured by the Planck mission. Direct numerical simulations can be used to check our predictions and to investigate the question of non-Gaussianity through the measure of intermittency.

Publication DOI: https://doi.org/10.3390/universe6070098
Additional Information: © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/)
Last Modified: 16 May 2024 07:14
Date Deposited: 17 Jul 2020 08:23
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Related URLs: https://www.mdp ... 218-1997/6/7/98 (Publisher URL)
PURE Output Type: Article
Published Date: 2020-07-16
Accepted Date: 2020-07-14
Authors: Galtier, Sébastien
Laurie, Jason (ORCID Profile 0000-0002-3621-6052)
Nazarenko, Sergey



Version: Published Version

License: Creative Commons Attribution

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