A pressure parametric dark energy model

TL;DR

This paper introduces a new pressure parametric dark energy model in a flat FRW universe, constrains it with observational data, and analyzes its evolution and deviation from the standard $\\Lambda$CDM model, including future universe fate.

Contribution

The paper proposes a novel pressure parametric dark energy model and reconstructs it into quintessence and phantom scenarios, providing observational constraints and diagnostic analyses.

Findings

Universe slightly favors quintessence behavior.

Model shows deviation from $\\Lambda$CDM at high redshifts.

Phantom case leads to a little rip in the future.

Abstract

In this paper, we propose a new pressure parametric model of the total cosmos energy components in a spatially flat Friedmann-Robertson-Walker (FRW) universe and then reconstruct the model into quintessence and phantom scenarios, respectively. By constraining with the datasets of the type Ia supernova (SNe Ia), the baryon acoustic oscillation (BAO) and the observational Hubble parameter data(OHD), we find that $\Omega_{m0}=0.270^{+0.039}_{-0.034}$ at the 1$\sigma$ level and our universe slightly biases towards quintessence behavior. Then we use two diagnostics including $Om(a)$ diagnostic and statefinder to discriminate our model from the cosmology constant cold dark matter ($\Lambda$CDM) model. From $Om(a)$ diagnostic, we find that our model has a relatively large deviation from the $\Lambda$CDM model at high redshifts and gradually approaches the $\Lambda$CDM model at low redshifts and in the future evolution, but they can be easily differentiated from each other at the 1$\sigma$ level all along. By the statefinder, we find that both of quintessence case and phantom case can be well distinguished from the $\Lambda$CDM model and will gradually deviate from each other. Finally, we discuss the fate of universe evolution (named the rip analysis) for the phantom case of our model and find that the universe will run into a little rip stage.