Galaxy clusters are excellent natural laboratories to study a wide variety of physical phenomena at the edge between cosmology and astrophysics. Their mass profiles can be reconstructed from the motions of member galaxies, the X-ray emission of the hot intracluster gas, and gravitational lensing. These complementary probes offer a way to investigate dark matter and test gravity, while also shedding light on how galaxies evolve in dense environments.
In this seminar, I will focus on galaxy kinematics, whose potential has been significantly growing in the last decade, thanks to large spectroscopic surveys and advances in dynamical modelling. I will show how kinematic measurements, combined with lensing data, can be used to test departures from General Relativity and constrain models of dark matter. I will also discuss what they reveal about the properties cluster galaxies and about the high-mass end of the concentration–mass relation. These applications will be illustrated with recent results from CLASH-VLT and CHEX-MATE clusters, as well as from the analysis of a new DESI spectroscopic catalogue of the Coma cluster.