Constraining Cluster Virialization Mechanism and Cosmology Using Thermal-SZ-selected Clusters from Future CMB Surveys

Abstract We forecast the number of galaxy clusters that can be detected via thermal Sunyaev–Zel’dovich (tSZ) signals by future cosmic microwave background (CMB) experiments, primarily wide area survey CMB-S4 experiment but also CMB-S4's smaller de-lensing and proposed CMB-HD experiment. predict will detect 75,000 with its f sky = 50% 14,000 deep 3%. Of these, approximately 1350 at z ? 2, a regime is difficult to probe optical or X-ray surveys. assume same as S4-Wide, find three times more overall an order magnitude 2 than CMB-S4. These results include galactic extragalactic foregrounds along atmospheric instrumental noise. Using CMB-cluster lensing calibrate cluster tSZ–mass scaling relation, we combine counts primary CMB obtain cosmological constraints for two-parameter extension standard model (?CDM + ? m ? w 0 ). In addition constraining ? ( ) ?1%, both surveys enable ?2.5–4.5 detection , substantially strengthening CMB-only constraints. study evolution intracluster medium modeling virialization v( tight from CMB-S4, further factors four improvement CMB-HD.