Non-linear Power Spectrum including Massive Neutrinos: the Time-RG Flow
  Approach
  Future large scale structure observations are expected to be sensitive to
small neutrino masses, of the order of 0.05 eV or more. However, forecasts are
based on the assumption that by the time at which these datasets will be
available, the non-linear spectrum in presence of neutrino mass will be
predicted with an accuracy at least equal to the neutrino mass effect itself,
i.e. about 3%. Motivated by these considerations, we present the computation of
the non-linear power spectrum of LambdaCDM models in the presence of massive
neutrinos using the Renormalization Group time-flow approach, which amounts to
a resummation of perturbative corrections to the matter power spectrum to all
orders. We compare our results with those obtained with other methods, i.e.
linear theory, one-loop perturbation theory and N-body simulations and show
that the time-RG method improves the one-loop method in fitting the N-body
data, especially in determining the suppression of the matter power spectrum
when neutrino are massive with respect to the linear power spectrum.
