Probing dark energy with redshift-drift

TL;DR

Future redshift-drift measurements, like the Sandage-Loeb signal, can significantly enhance our understanding of dark energy by constraining its properties and breaking parameter degeneracies when combined with CMB data.

Contribution

This paper quantifies the potential of future redshift-drift measurements to constrain dynamical dark energy parameters and improve cosmological constraints when combined with CMB data.

Findings

Redshift-drift measurements can constrain $w_0$ and $w_a$ parameters.

Combining with CMB data breaks degeneracies in cosmological parameters.

Future spectrographs like CODEX can significantly improve dark energy constraints.

Abstract

Future redshift-drift measurements (also known as Sandage-Loeb signal) will be crucial to probe the so called "redshift desert", thus providing a new tool for cosmological studies. In this paper we quantify the ability of a future measurement of the Sandage-Loeb signal by a CODEX-like spectrograph to constrain a phenomenological parametrization of dynamical dark energy, specifically by obtaining constraints on $w_0$ and $w_a$. We also demonstrate that if used alongside CMB data, the Sandage-Loeb measurements will be able to break degeneracies between expansion parameters, thus greatly improving cosmological constraints.