Neutrino-pair bremsstrahlung from nucleons in the condensed pion field: revisited

At temperatures less than a few MeV, the efficiency of the neutrino-pair bremsstrahlung from nucleons interracting with the condensed pion field is much less than previously estimated by other authors. The physical reason for this is a periodic structure of the developed pion condensate. The repeated interactions of a nucleon with the periodic pion field modify the nucleon spectrum, which is split into two bands. The energy gap between the bands is about a few MeV or larger, even if the amplitude of the pion field is small compared with the pion mass.