Constraints on the Phase Plane of the Dark Energy Equation of State

TL;DR

This paper uses current observational data to constrain dark energy models in the w-w' phase plane, ruling out several models at 68.3% confidence and supporting thawing and freezing quintessence.

Contribution

It provides updated constraints on dark energy models in the w-w' plane using recent SN Ia, CMB, and BAO data, focusing on the viability of different theoretical models.

Findings

Cosmological constant and certain fluid models are ruled out at 68.3% confidence.

Thawing and freezing quintessence models are consistent with current data.

All considered models are compatible at 95.4% confidence.

Abstract

Classification of dark energy models in the plane of w and w', where w is the dark energy equation of state and w' its time-derivative in units of the Hubble time, has been studied in the literature. We take the current SN Ia, CMB and BAO data, invoke a widely used parametrization of the dark energy equation of state, and obtain the constraints on the w -w' plane. We find that dark energy models including the cosmological constant, phantom, non-phantom barotropic fluids, and monotonic up-rolling quintessence are ruled out at the 68.3% confidence level based on the current observational data. Down-rolling quintessence, including the thawing and the freezing models, is consistent with the current observations. All the above-mentioned models are still consistent with the data at the 95.4% confidence level.