Confidence contours (68/95%) in the Ω_m − σ₈ plane for various datasets (CMB and X-ray clusters) and assumptions (three neutrinos with free masses or only one fixed to the standard 0.06 eV value). For the clusters-only cases, A_T − M is fixed to the Planck cluster calibration and additional uniform priors on Ω_m and H₀ have been applied (see Sect. 4.1 for details). The “CMB + X-ray clusters” contours with free calibration (not shown on this figure) are again identical to the “CMB” contours.