Signature of HDM clustering at Planck angular scales

Abstract

We present the CMB anisotropy induced by the non-linear perturbations in the massive neutrino density associated to the non-linear gravitational clustering. We show that the non-linear time varying potential induced by the gravitational clustering process generates metric perturbations that affect the time evolution of the density fluctuations in all the components of the expanding Universe, leaving imprints on the CMB anisotropy power spectrum at subdegree angular scales. For a neutrino fraction in agreement with that indicated by the astroparticle and nuclear physics experiments and a cosmological accreting mass comparable with the mass of known clusters, we find that CMB anisotropy measurements with {\sc Planck} angular resolution and sensitivity possibly combined to other precise cosmological observations will allow the detection of the dynamical, linear and non-linear effects of the neutrino gravitational clustering.