Linear dark energy equation of state revealed by supernovae?

TL;DR

This paper tests whether the dark energy equation of state is linear using supernova data and finds current data consistent with linearity up to redshift 1, with no significant deviations detected.

Contribution

It introduces a novel test for the linearity of the dark energy equation of state and applies it to supernova datasets, confirming linearity within current observational limits.

Findings

SN Ia data are well described by a linear dark energy equation of state up to z=1

No significant evidence of deviation from linearity in the data

Current data may limit the ability to detect more complex dark energy behaviors

Abstract

In this letter we propose a test to detect the linearity of the dark energy equation of state, and apply it to two different Type Ia Supernova (SN Ia) data sets, Union2.1 and SNLS3. We find that: a. current SN Ia data are well described by a dark energy equation of state linear in the cosmic scale factor a, at least up to a redshift z = 1, independent of the pivot points chosen for the linear relation; b. there is no significant evidence of any deviation from linearity. This apparent linearity may reflect the limit of dark energy information extractable from current SN Ia data.