Distinguishability of scalar field models of dark energy with time variable equation of state parameter

TL;DR

This paper investigates whether current and future observational data can differentiate between scalar field dark energy models with varying Lagrangians and time-dependent equations of state, finding potential distinguishability especially for decreasing EoS parameters.

Contribution

It analyzes the distinguishability of scalar field dark energy models with different Lagrangians and evolving equations of state using observational data.

Findings

Models with decreasing EoS parameters can be distinguished with upcoming data.

Models with increasing EoS parameters are practically indistinguishable.

Scalar field Lagrangians may be identified by future observations for decreasing EoS models.

Abstract

The possibility of distinguishing of scalar field models of dark energy with different Lagrangians and time variable equation of state parameter by available observational data is analyzed. The multicomponent cosmological models with the scalar field with either Klein-Gordon or Dirac-Born-Infeld Lagrangians as dark energy and the monotonic decreasing and increasing equation of state parameters are considered. It is concluded that scalar field models of dark energy with decreasing and increasing EoS parameters should be distinguishable at the accuracy level of forthcoming observational data. The Lagrangians of scalar fields could be distinguished by expected observational data (Planck, SDSS etc.) in the case of decreasing EoS parameter, but are practically indistinguishable in the case of increasing one.