Photoneutrino energy losses in strong magnetic fields

The energy losses by photoneutrinos is computed in the presence of a magnetic field of 10¹³ G, typical of neutron stars. Plasma effects are not included. The results indicate that for T≥10⁸ °K and densities ρ≥10⁴ g/cm³, the presence of a strong H field decreases the energy losses by at the most a factor between ten and a hundred in the region up to ρ≃10⁶ g/cm³. At higher densities the neutrino emissivities are almost identical. These effects are temperature-dependent and they are less and less pronounced when T≥5×10⁸ °K.