Discriminating secondary from primary non-Gaussian signals
Jean‐Luc Starck, P. Abrial, Y. Moudden, N. Aghanim, O. Forni · 2007
One of the goals in cosmology is to understand the formation and evolution of the structures resulting from the growth of initial density perturbations.Recent Cosmic Microwave Background (CMB) observations indicate that the latter essentially came out of Gaussian distributed quantum fluctuations in the inflationary scenario.However, topological defects (e.g.cosmic strings) could contribute to the signal.One of their important footprint would be the predicted non-Gaussian distribution of the temperature anisotropies.In addition, other sources of non-Gaussian signatures do contribute to the signal, in particular the Sunyaev-Zel'dovich effect of galaxy clusters [01].In this general context and motivated by the PLANCK experiment, we address the question of finding and discriminating between the different non-Gaussian signatures using both wavelet and curvelet transforms on the sphere to analyse simulated data.