Beschreibung
Galaxy cluster cosmology has proven to be a reliable probe not only for standard LCDM models, but also for testing gravity and modified physics. In this talk, I present my work on a Growth-Geometry split of the matter density parameter (Omega_m) within the context of LCDM, utilizing South Pole Telescope (SPT) and Dark Energy Survey (DES) data. By evaluating which of these two components is more tightly constrained by cluster data, we can determine whether galaxy clusters provide stronger constraints on the expansion history of the universe or on the growth and collapse of large-scale structures.