New Upper Limit on the Total Neutrino Mass from the 2 Degree Field Galaxy Redshift Survey

We constrain $f_{\nu }\equiv {\Omega }_{\nu }/{\Omega }_{\mathrm{m}}$, the fractional contribution of neutrinos to the total mass density in the Universe, by comparing the power spectrum of fluctuations derived from the 2 Degree Field 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 $0.1<{\Omega }_{\mathrm{m}}<0.5$, and assuming the scalar spectral index $n=1$. This translates to an upper limit on the total neutrino mass $m_{\nu ,\mathrm{t}\mathrm{o}\mathrm{t}}<1.8\mathrm{e}\mathrm{V}$ for “concordance” values of ${\Omega }_{\mathrm{m}}$ and the Hubble constant.