The SZ effect as a cosmic thermometer: Methods, results, future prospects

International audienceWe report recent progress in testing the scaling law of the CMB temperature as a function of redshift. By using an up-to-date sample of multifrequency SZ data of 13 galaxy clusters, we have extracted the CMB temperature values at different redshifts, and we found no significant evidence of deviations from the linear scaling, as expected in the framework of standard cosmology. The robustness of the method, even with the limitations set by the current level of the observational uncertainties, has been tested by using two different approaches. Therefore, we expect a significant improvement of the present results from currently active and near-future SZ experiments