  The differential rates and emissivities of neutrino pairs from an equilibrium
plasma are calculated for the wide range of density and temperature encountered
in astrophysical systems. New analytical expressions are derived for the
differential emissivities which yield total emissivities in full agreement with
those previously calculated. The photon and plasmon pair production and
absorption kernels in the source term of the Boltzmann equation for neutrino
transport are provided. The appropriate Legendre coefficients of these kernels,
in forms suitable for multi-group flux-limited diffusion schemes are also
computed.
