Constraints on oscillating dark energy models

TL;DR

This paper investigates observational constraints on an oscillating dark energy model driven by a conformally coupled phantom scalar field, comparing its viability to the standard Lambda Cold Dark Matter model and linear dynamical models.

Contribution

It provides the first detailed observational analysis of an oscillating dark energy scenario with a conformally coupled scalar field, contrasting it with LambdaCDM and linear dynamical models.

Findings

LambdaCDM is favored over the oscillating dark energy model.

Oscillating dark energy is favored over linearly decaying dark energy.

The model's attractor behavior aligns with current cosmological observations.

Abstract

The oscillating scenario of route to Lambda was recently proposed by us arXiv:0704.1651 as an alternative to a cosmological constant in a explanation of the current accelerating universe. In this scenario phantom scalar field conformally coupled to gravity drives the accelerating phase of the universe. In our model $\Lambda$CDM appears as a global attractor in the phase space. In this paper we investigate observational constraints on this scenario from recent measurements of distant supernovae type Ia, CMB R shift, BAO and $H(z)$ observational data. The Bayesian methods of model selection are used in comparison the model with concordance $\Lambda$CDM one as well as with model with dynamical dark energy parametrised by linear form. We conclude that $\Lambda$CDM is favoured over FRW model with dynamical oscillating dark energy. Our analysis also demonstrate that FRW model with oscillating dark energy is favoured over FRW model with decaying dark energy parametrised in linear way.