2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/7022We outline main arguments in favor of cosmological X-ray surveys of galaxy clusters. We summarize recent advances in our understanding of cluster physics. After a short review of past surveys, we present the scientific motivations of the XMM Large Scale Structure survey. We further illustrate how such a survey can help constrain the nature of the dark energy as well as cluster scaling law evolution, i.e. non gravitational physics.8 pages, 3 figuresAstrophysicstext