Distinguish three time-dependent dark energy models using statefinder pairs with error bars and Bayesian evidence

TL;DR

This study compares three time-dependent dark energy models using statefinder pairs with error bars and Bayesian evidence, finding one model more consistent with observational data and statistically favored over the others.

Contribution

It introduces a combined approach of statefinder analysis with error bars and Bayesian evidence to distinguish dark energy models using current observational data.

Findings

One model has a more compact error region in statefinder space.

Bayesian evidence favors this model significantly over the others.

The model with a specific equation of state is identified as a preferable candidate.

Abstract

In this work, two completely different approaches, statefinder with error bars and Bayesian evidence, are used to distinguish and judge three time-dependent dark energy models. The parameters constrain for the three dark energy models are given using the current cosmic observational data sets : $Planck$ 2015, SNIa, BAO and OHD. Using the statefinder pairs with error bars, we find that the error region of the dark energy model, whose equation of state parameter is given by $w(a) = w_0+w_3\frac{1-a}{a^2+(1-a)^2}$, is relativity compact than the other two models during the all the evolving history. Meanwhile, the Bayesian evidence also provide that this model is significantly better than the other two models and the other two models are inconclusive. Then, there are reasons for believing that this model is a preferential candidate in dark energy investigation rather than the other two.