  We apply statistical tests, based on the study of thecoefficients in a
wavelet decomposition, to a cosmological signal: the Cosmic Microwave
Background (CMB) anisotropies. The latter represent the superposition of
primary anisotropy imprints of the initial density perturbations and secondary
anisotropies due to photon interactions after recombination. In an inflationary
scenario with Gaussian distributed fluctuations, we study the statistical
signature of the secondary effects. More specifically, we investigate the
dominant effects arising from the Sunyaev-Zel'dovich effect of galaxy clusters.
Our study predicts the non-Gaussian signature of these secondary anisotropies
and its detectability in the context of the future CMB satellite Planck
Surveyor.
