Constraining the dark-energy equation of state with cosmological data

TL;DR

This paper uses recent cosmological data to constrain dark energy's equation of state, suggesting it may be below -1 and consistent with phantom energy models, indicating a potential departure from the cosmological constant.

Contribution

It introduces a phenomenological approach to analyze the evolution of dark energy using high-precision observational data, highlighting the possibility of phantom energy.

Findings

Dark energy equation of state likely below -1

Phantom energy models are consistent with current data

Supports departure from cosmological constant paradigm

Abstract

Recently, the observed equation of state for dark energy appears to favor values below $-1$. The tendency implies that the nature of dark energy may be quite different from that of the cosmological constant. In view of the adjustment on the equation of state keeps decreasing, the introduction of the phantom energy seems inevitable. By employing observational constraints from supernovae and from the acoustic scale in which the accuracy of the data has become extraordinary, we apply a phenomenological scenario to be acquainted with the evolution of our universe. The demonstration on the constrained unfolding of the phantom energy shows the model has high consistency with the current observation.