Probing dynamics of dark energy with latest observations

Abstract

We examine the validity of the ΛCDM model and probe the dynamics of dark energy with the latest astronomical observations. Using the Om(z) diagnosis, we find that various kinds of observational data are in tension within the ΛCDM framework. We then allow for dynamics of dark energy and investigate the constraint on dark energy parameters. We find that for two different kinds of parametrisations of the equation of state parameter w, a combination of current data mildly favours an evolving w, although the significance is not sufficient for it to be supported by Bayesian evidence. A forecast of the DESI survey shows that the dynamics of dark energy could be detected at the 7σ confidence level and would be decisively supported by Bayesian evidence, if the best-fit model of w derived from current data is the true model.