Combining Planck data with large scale structure information gives a strong neutrino mass constraint

We present the strongest current cosmological upper limit on the neutrino mass of m_<0. 18 eV (95% confidence). It is obtained by adding observations of the large-scale matter power spectrum from the WiggleZ Dark Energy Survey to observations of the cosmic microwave background data from the Planck surveyor, and measurements of the baryon acoustic oscillation scale. The limit is highly sensitive to the priors and assumptions about the neutrino scenario. We explore scenarios with neutrino masses close to the upper limit (degenerate masses), neutrino masses close to the lower limit where the hierarchy plays a role, and the addition of massive or massless sterile species.