Constraints on the neutrino mass and the primordial magnetic field from the matter density fluctuation parameter ${\sigma }_8$

We have made an analysis of limits on the neutrino mass based upon the formation of large-scale structure in the presence of a primordial magnetic field. We find that a new upper bound on the neutrino mass is possible based upon fits to the cosmic microwave background and matter power spectrum when the existing independent constraints on the matter density fluctuation parameter ${\sigma }_8$ and the primordial magnetic field are taken into account.