https://doi.org/10.1140/epjc/s10052-020-8226-x
Regular Article - Theoretical Physics
Primordial universe with the running cosmological constant
1
Núcleo Cosmo-ufes and PPGCosmo, Departamento de Física, Universidade Federal do Espírito Santo, 29075-910, Vitória, ES, Brazil
2
National Research Nuclear University MEPhI, Kashirskoe sh. 31, 115409, Moscow, Russia
3
Departament of Physics, Southern University of Science and Technology, 518055, Shenzhen, China
4
Departamento de Física, ICE, Universidade Federal de Juiz de Fora, 36036-100, Juiz de Fora, MG, Brazil
Received:
31
January
2020
Accepted:
9
July
2020
Published online:
14
September
2020
Theoretically, the running of the cosmological constant in the IR region is not ruled out. On the other hand, from the QFT viewpoint, the energy released due to the variation of the cosmological constant in the late Universe cannot go to the matter sector. For this reason, the phenomenological bounds on such a running are not sufficiently restrictive. The situation can be different in the early Universe when the gravitational field was sufficiently strong to provide an efficient creation of particles from the vacuum. We develop a framework for systematically exploring this possibility. It is supposed that the running occurs in the epoch when the Dark Matter already decoupled and is expanding adiabatically, while the usual matter should be regarded approximately massless and can be abundantly created from vacuum due to the decay of vacuum energy. By using the handy model of Reduced Relativistic Gas for describing the warm Dark Matter, we consider the dynamics of both cosmic background and linear perturbations and evaluate the impact of the vacuum decay on the matter power spectrum and to the first CMB peak. Additionally, using the combined SNIa+BAO data, we find the best-fit values for the free parameters of the model.
I. L. Shapiro: On leave from Tomsk State Pedagogical University.
© The Author(s) 2020
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
Funded by SCOAP3