Presentation #433.01 in the session Cosmic Microwave Background.
Galaxy clusters are the largest gravitationally bound objects in the Universe and are remarkable cosmological probes. Measuring their abundances as a function of mass and redshift can reveal a great deal of information about the parameters that influence geometry and structure growth in the Universe like dark energy and neutrinos. In this talk, I will present the expected number of galaxy clusters that can be detected via the thermal Sunyaev-Zeldovich (tSZ) signals by future cosmic microwave background (CMB) experiments, namely the upcoming CMB-S4 and the futuristic CMB-HD experiments. Using their weak-gravitational lensing signatures on the cosmic microwave background (CMB) to internally calibrate cluster tSZ-mass scaling relation, I will show that combining cluster abundance measurements with primary CMB can constrain the error on dark energy equation of state to sub-percent accuracy and can also enable a ≳3σ detection of the sum of neutrino masses. Finally, I will also show how these future measurements can help us understand the virialisation mechanism of clusters and the evolution of the intra-cluster medium.