Neutrino mass limits from SDSS, 2dFGRS and WMAP

Abstract

We investigate whether cosmological data suggest the need for massive neutrinos. We employ galaxy power spectrum measurements from the Sloan Digital Sky Survey (SDSS) and the Two Degree Field Galaxy Redshift Survey (2dFGRS), along with cosmic microwave background (CMB) data from the Wilkinson Microwave Anisotropy Probe (WMAP) and 27 other CMB experiments. We also use the measurement of the Hubble parameter from the Hubble Space Telescope (HST) Key Project. We find the sum of the neutrino masses to be smaller than 0.75 eV at 2σ(1.1 eV at 3σ).

Figures (2)

• Figure 1: Upper panel: CMB TT power spectra. Lower panel: Galaxy power spectra. The curves are the spectra for $\Sigma=0.28$ eV (solid, best-fit parameters; the galaxy power spectrum is shown for the SDSS best-fit normalization), $\Sigma=1.5$ eV (dotted) and $\Sigma=3$ eV (dashed). The latter two spectra have all other parameters (except the normalization, bias parameters and $\Omega_{cdm}$) fixed at the best-fit values. All curves are for a flat universe. The CMB TT spectra are normalized to have identical powers at the first peak. The galaxy power spectra are normalized to have identical powers at $k=0.017\ h$/Mpc. In the upper panel, the data points marked by circles (squares) represent the binned TT spectrum from WMAP (pre-WMAP experiments). In the lower panel, the data points marked by circles (squares) represent the galaxy power spectra from the 17 SDSS (32 2dFGRS) bands used in our analysis.
• Figure 2: $\Delta \chi^2$ vs $\Sigma$ from an analysis of SDSS, 2dFRGS, WMAP and other CMB data with $b_{SDSS}$ and $b_{2dF}$ free.