Constraints on Massive Neutrinos from the CFHTLS Angular Power Spectrum

TL;DR

This study uses the CFHTLS galaxy angular power spectrum to place new constraints on the total neutrino mass and the effective number of neutrino species, leveraging non-linear matter power spectrum models and combining with other cosmological data.

Contribution

It provides the first constraints on neutrino properties using CFHTLS data with a non-linear power spectrum model calibrated from N-body simulations.

Findings

Upper limit on total neutrino mass: <0.29 eV

Effective number of neutrino species: 4.17^{+1.62}_{-1.26}

Constraints improve when including additional large-scale structure data

Abstract

We use the galaxy angular power spectrum at $z\sim0.5-1.2$ from the Canada-France-Hawaii-Telescope Legacy Survey Wide fields (CFHTLS-Wide) to constrain separately the total neutrino mass $\sum{m_\nu}$ and the effective number of neutrino species $N_{\rm{eff}}$. This survey has recently benefited from an accurate calibration of the redshift distribution, allowing new measurements of the (non-linear) matter power spectrum in a unique range of scales and redshifts sensitive to neutrino free streaming. Our analysis makes use of a recent model for the effect of neutrinos on the weakly non-linear matter power spectrum derived from accurate N-body simulations. We show that CFHTLS, combined with WMAP7 and a prior on the Hubble constant provides an upper limit of $\sum{m_\nu}<0.29\,$eV and $N_{\rm{eff}} =4.17^{+1.62}_{-1.26}$ (2$\,\sigma$ confidence levels). If we omit smaller scales which may be affected by non-linearities, these constraints become $\sum{m_\nu}<0.41\,$eV and $N_{\rm{eff}} =3.98^{+2.02}_{-1.20}$ (2$\,\sigma$ confidence levels). Finally we show that the addition of other large scale structures probes can further improve these constraints, demonstrating that high redshift large volumes surveys such as CFHTLS are complementary to other cosmological probes of the neutrino mass.