Closure in flux-limited neutrino diffusion and two-moment transport

Two-dimensional maximum entropy closure and various standard one-dimensiona l closures in flux-limited neutrino diffusion and two-moment transport are compared against direct numerical solutions of the neutrino Boltzmann equat ion. The approximate transport based on particular closures of the moment e quations is rated by testing so-called weak equivalence of the first three moments of the neutrino radiation field. Additionally we consider strong eq uivalence of the maximum entropy angular model distribution. Our calculatio ns are performed on two different matter backgrounds and involve several ne utrino energies. As an alternative multiple energy test we look at the beha vior of spectral and energy-averaged Eddington factors. Among the closures considered, two-dimensional maximum entropy closure is found to overall app roximate most closely the full transport solutions.