How to add massive neutrinos to your ΛCDM simulation – extending cosmology rescaling algorithms

Abstract

ABSTRACT Providing accurate predictions for the spatial distribution of matter and luminous tracers in the presence of massive neutrinos is an important task, given the imminent arrival of highly accurate large-scale structure observations. In this work, we address this challenge by extending cosmology-rescaling algorithms to massive neutrino cosmologies. In this way, a ΛCDM simulation can be modified to provide non-linear structure formation predictions in the presence of a hot component of arbitrary mass, and, if desired, to include non-gravitational modifications to the clustering of matter on large scales. We test the accuracy of the method by comparing its predictions to a suite of simulations carried out explicitly including a neutrino component in its evolution equations. We find that, for neutrino masses in the range Mν ∈ [0.06, 0.3] eV the matter power spectrum is recovered to better than $1{{\ \rm per\ cent}}$ on all scales k < 2 h Mpc−1. Similarly, the halo mass function is predicted at a few per cent level over the range Mhalo ∈ [1012, 1015] h−1 M⊙, and so do also the multipoles of the galaxy two-point correlation function in redshift space over r ∈ [0.1, 200] h−1 Mpc. We provide parametric forms for the necessary transformations, as a function of Ωm and Ων for various target redshifts.