On the road to percent accuracy III: non-linear reaction of the matter power spectrum to massive neutrinos

TL;DR

This paper develops an analytical model using the halo model reaction framework to accurately predict the non-linear matter power spectrum affected by massive neutrinos, achieving percent-level precision up to small scales.

Contribution

It demonstrates how the halo model reaction framework, combined with standard simulations, can accurately predict the non-linear matter power spectrum with massive neutrinos.

Findings

Percent-level accuracy in matter power spectrum prediction up to k=10 h/Mpc.

Refining halo properties with N-body simulations improves accuracy to better than 1%.

Framework effectively models beyond-ΛCDM physics in the non-linear regime.

Abstract

We analytically model the non-linear effects induced by massive neutrinos on the total matter power spectrum using the halo model reaction framework of Cataneo et al. 2019. In this approach the halo model is used to determine the relative change to the matter power spectrum caused by new physics beyond the concordance cosmology. Using standard fitting functions for the halo abundance and the halo mass-concentration relation, the total matter power spectrum in the presence of massive neutrinos is predicted to percent-level accuracy, out to $k=10 \, h \, {\rm Mpc}^{-1}$. We find that refining the prescriptions for the halo properties using $N$-body simulations improves the recovered accuracy to better than 1%. This paper serves as another demonstration for how the halo model reaction framework, in combination with a single suite of standard $\Lambda$CDM simulations, can recover percent-level accurate predictions for beyond-$\Lambda$CDM matter power spectra, well into the non-linear regime.