Impact of massive neutrinos on nonlinear matter power spectrum

TL;DR

This paper analytically studies how massive neutrinos affect the nonlinear matter power spectrum, revealing enhanced suppression effects that improve constraints on neutrino mass in galaxy surveys.

Contribution

It provides the first analytical model of the nonlinear matter power spectrum including massive neutrinos using cosmological perturbation theory.

Findings

Nonlinear suppression of power spectrum is greater than linear predictions.

The model can constrain total neutrino mass with an accuracy of ~0.07 eV.

Enhanced effects extend the range of wavenumbers for analysis.

Abstract

We present the first attempt to analytically study the nonlinear matter power spectrum for a mixed dark matter (cold dark matter plus neutrinos of total mass ~0.1eV) model based on cosmological perturbation theory. The suppression in the power spectrum amplitudes due to massive neutrinos is, compared to the linear regime, enhanced in the weakly nonlinear regime where standard linear theory ceases to be accurate. We demonstrate that, thanks to this enhanced effect and the gain in the range of wavenumbers to which the PT prediction is applicable, the use of such a nonlinear model may enable a precision of sigma(m_nu,tot) ~ 0.07eV in constraining the total neutrino mass for the planned galaxy redshift survey, a factor of 2 improvement compared to the linear regime.