Journal Article

Cosmic evolution of dark energy in a generalized Rastall gravity

Lin, Kai, Qian, Wei-Liang

2020

Overview

In this work, we propose a scheme for cosmic evolution in a generalized Rastall gravity. In our approach, the role of dark energy is taken by the non-conserved sector of the stress energy–momentum tensor. The resultant cosmic evolution is found to naturally consists of three stages, namely, radiation dominated, ordinary matter dominated, as well as dark energy and dark matter dominated eras. Furthermore, for the present model, it is demonstrated that the eventual fate of the Universe is mostly insensitive to the initial conditions, in contrast to the standard Λ CDM model. In particular, the solution displays the properties of a dynamic attractor, which is reminiscent of quintessence and k-essence models. Subsequently, the cosmic coincidence problem is averted. The amount of deviation from a conserved stress energy–momentum tensor is shown to be more remarkable during the period when the dark energy evolves more rapidly. On the other hand, the conservation law is largely restored for the infinite past and future. The implications of the present approach are addressed.

• Publisher: Springer Berlin Heidelberg,Springer,Springer Nature B.V,SpringerOpen
• Subject: Astronomy / Astrophysics and Cosmology / Big Bang theory / Cosmogony / Dark energy / Dark matter / Dark matter (Astronomy) / Elementary Particles / Energy conservation / Evolution / Gravitation / Hadrons / Heavy Ions / Initial conditions / Mathematical analysis / Measurement Science and Instrumentation / Momentum / Nuclear Energy / Nuclear Physics / Physics / Physics and Astronomy / Quantum Field Theories / Quantum Field Theory / Quintessence (cosmology) / Regular Article - Theoretical Physics / String Theory / Tensors