Cosmological evolution of interacting dark energy in Lorentz violation

TL;DR

This paper investigates a cosmological model where dark energy interacts with other components via Lorentz violation, analyzing its dynamics, stability, and observational implications.

Contribution

It introduces a novel interacting scalar field model with Lorentz violation and analyzes its cosmological evolution and observational consistency.

Findings

Sequence of radiation, dark matter, and dark energy phases confirmed.

Universe can enter a phantom phase with constant potential.

Effective gravitational constant varies over time with Lorentz violation.

Abstract

The cosmological evolution of an interacting scalar field model in which the scalar field interacts with dark matter, radiation, and baryon via Lorentz violation is investigated. We propose a model of interaction through the effective coupling $\bar{\beta}$. Using dynamical system analysis, we study the linear dynamics of an interacting model and show that the dynamics of critical points are completely controlled by two parameters. Some results can be mentioned as follows. Firstly, the sequence of radiation, the dark matter, and the scalar field dark energy exist and baryons are sub dominant. Secondly, the model also allows the possibility of having a universe in the phantom phase with constant potential. Thirdly, the effective gravitational constant varies with respect to time through $\bar{\beta}$. In particular, we consider a simple case where $\bar{\beta}$ has a quadratic form and has a good agreement with the modified $\Lambda$CDM and quintessence models. Finally, we also calculate the first post--Newtonian parameters for our model.