MassiveNuS: cosmological massive neutrino simulations

Abstract

The non-zero mass of neutrinos suppresses the growth of cosmic structure on small scales. Since the level of suppression depends on the sum of the masses of the three active neutrino species, the evolution of large-scale structure is a promising tool to constrain the total mass of neutrinos and possibly shed light on the mass hierarchy. In this work, we investigate these effects via a large suite of N -body simulations that include massive neutrinos using an analytic linear-response approximation: the Cosmological Massive Neutrino Simulations (MassiveNuS). The simulations include the effects of radiation on the background expansion, as well as the clustering of neutrinos in response to the nonlinear dark matter evolution. We allow three cosmological parameters to vary: the neutrino mass sum M ν in the range of 0-0.6 eV, the total matter density Ω m , and the primordial power spectrum amplitude A s . The rms density fluctuation in spheres of 8 comoving Mpc/h (σ 8 ) is a derived parameter as a result. Our data products include N -body snapshots, halo catalogues, merger trees, raytraced galaxy lensing convergence maps for four source redshift planes between z s =1-2.5, and ray-traced cosmic microwave background lensing convergence maps. We describe the simulation procedures and code validation in this paper. The data are publicly available at

Neutrino effects on the morphology of cosmic large-scale structure

“…In addition, this smeared matter also patch the relatively thin parts in the denser sheetlike structures. Therefore, with ρ/ρ rising (ρ/ρ > 0.2), we first see a similar trend as we see in the former two scenarios but with mild amplitude; when ρ/ρ being high enough, the excursion set will turn into isolated virialized density peaks (balls), finally we see V 3 goes to below zero, corresponding to the suppression effect on mass function of massive halos in neutrino cosmology [43,44,76] ; i.e., ∆V 3 < 0, then ∆V 3 > 0 and finally ∆V 3 < 0. With ρ/ρ rising higher and higher, we find ∆V 3 approximates to zero asymptotically, since the small halos with higher concentrations [77] are less impacted by massive neutrinos, corresponding to the upturn at high k (> 1 hMpc −1 ) on P ν m /P f iducial m [76].…”

On the road to per cent accuracy – III. Non-linear reaction of the matter power spectrum to massive neutrinos

“…Banerjee & Dalal 2016;Bird et al 2018) in N-body codes. Ideally, we would carry out this test using the simulation outputs of codes other than cubep 3 m (e.g., Castorina et al 2015;Liu et al 2018). However, publicly available snapshots do not include runs for the pseudo cosmologies, which means we must resort to our simulations for these cases.…”

Status of Neutrino Properties and Future Prospects—Cosmological and Astrophysical Constraints

“…The level of complexity of Nbody simulations has been increasing over the years, so that the physical processes included in the simulations and the final results are much closer to the observations than they used to be at the beginning. Recent examples are given by the MassiveNuS [69] suite, based on the Gadget-2 code [70] modified to include the effects of massive neutrinos, the DEMNUni suite [71][72][73], the TianNu simulation [74][75][76], the BAHAMAS project [77], the gevolution simulations [78], and the nuCONCEPT simulations [79] (see also [80] for a method combining the particle and fluid descriptions) 7 . Nevertheless, the uncertainties related to the non-linear evolution of cosmological structures are still higher than those affecting the linear theory, therefore reducing the constraining power coming from the inclusion of those scales in cosmological analysis.…”