Probing dark energy with redshift drift

Future redshift-drift measurements (also known as the 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 Cosmic-Dynamics-Experiment-like spectrograph to constrain a phenomenological parametrization of dynamical dark energy, specifically by obtaining constraints on w₀ 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.