New Upper Limit on the Total Neutrino Mass from the 2 Degree Field Galaxy Redshift Survey (original) (raw)

A new upper limit on the total neutrino mass from the 2dF Galaxy Redshift Survey

Phys Rev Lett, 2002

We constrain f_nu = Omega_nu / Omega_m, the fractional contribution of neutrinos to the total mass density in the Universe, by comparing the power spectrum of fluctuations derived from the 2dF Galaxy Redshift Survey with power spectra for models with four components: baryons, cold dark matter, massive neutrinos and a cosmological constant. Adding constraints from independent cosmological probes we find f_nu < 0.13 (at 95% confidence) for a prior of 0.1< Omega_m <0.5, and assuming the scalar spectral index n=1. This translates to an upper limit on the total neutrino mass and m_nu,tot < 1.8 eV for "concordance" values of Omega_m and the Hubble constant. Very similar results are obtained with a prior on Omega_m from Type Ia supernovae surveys, and with marginalization over n.

Upper limits on neutrino masses from the 2dFGRS and WMAP: the role of priors

2003

Solar, atmospheric, and reactor neutrino experiments have confirmed neutrino oscillations, implying that neutrinos have non-zero mass, but without pinning down their absolute masses. While it is established that the effect of neutrinos on the evolution of cosmic structure is small, the upper limits derived from large-scale structure data could help significantly to constrain the absolute scale of the neutrino masses. In a recent paper the 2dF Galaxy Redshift Survey (2dFGRS) team provided an upper limit m_nu,tot < 2.2 eV, i.e. approximately 0.7 eV for each of the three neutrino flavours, or phrased in terms of their contributioin to the matter density, Omega_nu/Omega_m < 0.16. Here we discuss this analysis in greater detail, considering issues of assumed 'priors' like the matter density Omega_m and the bias of the galaxy distribution with respect the dark matter distribution. As the suppression of the power spectrum depends on the ratio Omega_nu/Omega_m, we find that th...

Weighing neutrinos using high redshift galaxy luminosity functions

Physical Review D, 2011

Laboratory experiments measuring neutrino oscillations indicate small mass differences between different mass eigenstates of neutrinos. The absolute mass scale is however not determined, with at present the strongest upper limits coming from astronomical observations rather than terrestrial experiments. The presence of massive neutrinos suppresses the growth of perturbations below a characteristic mass scale, thereby leading to a decreased abundance of collapsed dark matter halos. Here we show that this effect can significantly alter the predicted luminosity function (LF) of high redshift galaxies. In particular we demonstrate that a stringent constraint on the neutrino mass can be obtained using the well measured galaxy LF and our semianalytic structure formation models. Combining the constraints from the Wilkinson Microwave Anisotropy Probe 7 yr (WMAP7) data with the LF data at z˜4, we get a limit on the sum of the masses of 3 degenerate neutrinos Σmν<0.52eV at the 95% C.L. The additional constraints using the prior on Hubble constant strengthens this limit to Σmν<0.29eV at the 95% C.L. This neutrino mass limit is a factor ˜4 improvement compared to the constraint based on the WMAP7 data alone, and as stringent as known limits based on other astronomical observations. As different astronomical measurements may suffer from different set of biases, the method presented here provides a complementary probe of Σmν. We suggest that repeating this exercise on well measured luminosity functions over different redshift ranges can provide independent and tighter constraints on Σmν.