29 mai 2017
Clusters of galaxies are the largest (~ Mpc sizes) and the most massive (~1014-15 Msol) structures in the cosmic web. They enclose large quantities of hot baryonic gas emitting copious amounts X-ray photons, which allow to trace massive matter haloes out to large redshifts. For this reason, X-ray galaxy clusters are long-standing probes of the growth of large-scale structure: studies of their distribution in space and in mass are driven by their unique capability in constraining cosmological models and the nature of dark energy. I will select and describe important observational and modeling challenges related to cosmology with X-ray galaxy clusters, by presenting results and forecasts based on ongoing large-area surveys: X-CLASS, the XMM-XXL and SDSS-IV/SPIDERS. In particular, I will demonstrate the ability of a self-consistent approach combining X-rays, optical and weak-lensing measurements to study cosmological parameters and physical scaling relations of X-ray clusters.