Neutrino-Mass Effects on the CMB Anisotropies in a Cosmological Model with a Primordial Magnetic Field

In recent years neutrino oscillation experiments have showed that neutrinos have finite mass. One can determine the neutrino mass from neutrinoless double-beta decay experiments, but the exact mass of neutrinos is still unknown. However, we can also constrain the neutrino mass from a precise analysis of the CMB data, which constrains the mass to be smaller than 2 eV (2σ) in a standard ΛCDM model [1]. In recent studies it has beddn shown that a primordial magnetic field (PMF) exists, and it makes important effects on the CMB anisotropies. In this work, we constrain the total neutrino mass from the CMB anisotropies with the PMF effect. We thus a obtained a smaller upper limit on the neutrino mass, i.e. <1.3 eV(2σ). We will also discuss the dependence on the power law spectral index of the PMF and on the vector CMB anisotropies