1505.07148
DEMNUni: The clustering of large-scale structures in the presence of massive neutrinos
Castorina, et al
Analyse the clustering features of LSS in the presence of massive neutrinos, employing a set of large-volume, high-res cosmo N-body sims, where neutrinos are treated as a separated collisionless fluid. The volume of 8Gpc^3, combined with a res of about 8e10 Msun for the CDM component, represents a significant improvement over previous N-body sims in massive neutrino cosmologies. Show that most of the NL evolution is generated exclusively by the CDM component. Find that accounting only for the NL evolution of the CDM PS allows to recover the total matter PS with the same accuracy as the massless case. Indeed, show that, the most recent version of the halofit formula calibrated on LCDM simulations can be applied directly to the linear CDM PS without requiring additional fitting parameters in the massive case. As a second step, study the abundance and clustering properties of CDM haloes, confirming that, in massive neutrino cosmologies, the proper definition of the halo bias should be made with respect to the cold rather than the total matter distribution, as recently shown in the literature. Extend these results to the z space, finding that, when accounting for the massive neutrinos, an improper definition of the linear bias can lead to a systematic error of about 1-2% in the determination of the linear growth rate from anisotropic clustering. This result is quite important if future spectra galaxy surveys are considered, e.g. Euclid, as they are expected to measure the linear growth-rate with statistical errors less than about 3% at z<=1.
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