The effect of massive neutrinos on the matter power spectrum

We investigate the impact of massive neutrinos on the distribution of matter in the semi-non-linear regime (0.1 less than or similar to k less than or similar to 0.6 h Mpc-1). We present a suite of large-scale N-body simulations quantifying the scale-dependent suppression of the total matter power spectrum, resulting from the free-streaming of massive neutrinos out of high-density regions. Our simulations show a power suppression of 3.5-90 per cent at k similar to 0.6 h Mpc-1 for total neutrino mass, Sigma m(nu) = 0.05-1.9 eV, respectively. We also discuss the precision levels that future cosmological data sets would have to achieve in order to distinguish the normal and inverted neutrino mass hierarchies.