First Cosmological Constraints on Dark Energy from the Radial Baryon Acoustic Scale

TL;DR

This paper reports the first constraints on dark energy using radial baryon acoustic oscillations, providing new measurements of the universe's expansion and composition without relying on prior assumptions, and confirming consistency with a flat Lambda-CDM model.

Contribution

It introduces the first measurement of radial BAO at specific redshifts to constrain dark energy parameters independently of other assumptions.

Findings

Radial BAO measurements at z=0.24 and 0.43 provide new constraints.

Results are consistent with a flat Lambda-CDM cosmology.

Constraints on dark energy and matter density are the most stringent to date.

Abstract

We present cosmological constraints arising from the first measurement of the radial (line-of-sight) baryon acoustic oscillations (BAO) scale in the large scale structure traced by the galaxy distribution. Here we use these radial BAO measurements at z = 0.24 and z = 0.43 to derive new constraints on dark energy and its equation of state for a flat universe, without any other assumptions on the cosmological model: w = -1.14 +/- 0.39 (assumed constant), Omega_m = 0.24+0.06-0.05. If we drop the assumption of flatness and include previous cosmic microwave background and supernova measurements, we find w = -0.974 +/- 0.058, Omega_m = 0.271 +/- 0.015, and Omega_k = -0.002 +/- 0.006, in good agreement with a flat cold dark matter cosmology with a cosmological constant. To our knowledge, these are the most stringent constraints on these parameters to date under our stated assumptions.