Calibrating cluster number counts with CMB lensing

CMB Stage-4 experiments aim to reduce the uncertainties on the gravitational lensing potential by an order of magnitude compared to current measurements, and to also produce a Sunyaev-Zel'dovich (SZ) cluster catalog containing similar to 10(5) objects, two orders of magnitudes higher than what is currently available. In this paper we propose to combine these two observables and show that it is possible to calibrate the masses of the full Stage-4 cluster catalog internally owing to the high signal to noise measurement of the cosmic microwave background (CMB) lensing convergence field. We find that a CMB Stage-4 experiment will constrain the hydrostatic bias parameter to sub-percent accuracy. We also show constraints on a nonparametric Y - M relationship which could be used to study its evolution with mass and redshift. Finally we present a joint likelihood for thermal SZ (tSZ) flux and mass measurements, and show that it could lead to a similar to 5 sigma detection of the lower limit on the sum of the neutrino masses in the normal hierarchy (Sigma m(L/) = 60 meV) once combined with measurements of the primordial CMB and CMB lensing power spectra assuming a cosmic-variance-limited measurement of the optical depth to reionization.