Constraints on Massive Neutrinos from the CFHTLS Angular Power Spectrum
  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.
