Coherence effects and neutrino pair bremsstrahlung in neutron stars

We calculate the rate of energy radiation by bremsstrahlung of neutrino pairs by baryons in neutron stars employing a transport model where neutrinos couple to baryons with spectral width. The coherence effects, which are included by computing the self energies with fully dressed propagators, lead to the Landau–Pomeranchuk–Migdal suppression of the neutrino emission rates in the soft neutrino and high temperature limit. A microscopic evaluation of the bremsstrahlung rate by neutrons is carried out using the Brueckner theory of nuclear matter at finite temperatures.