The splashback radius in galaxy clusters
The splashback radius, which is the location of the minimum of the slope of the density profile of a dark matter halo, corresponds to the physical phase space boundary of the virialized region of a halo, it encodes dynamical information about halo structure and evolution. In this talk I will discuss in part the recent theoretical developments of understanding the splashback radius as a probe for cosmology, i.e. how it's location is sensitive to modified gravity and to dark matter models. I will also talk about the current status of observations of the splashback radius in galaxy clusters using DES, SPT and ACT and finally I will discuss what this feature may tell us about galaxy evolution within halos and what we have learnt from the current observations.