Angular fluctuations in the temperature of the cosmic background radiation in a universe with massive neutrinos

The possibility has been considered that the universe may have acquired its large-scale structure early, when a background of finite-mass neutrinos was present. A massive-neutrino background would have controlled the growth dynamics of protogalactic perturbations, thereby affecting temperature variations for the primordial electromagnetic radiation during the era when the plasma was becoming transparent. The present investigation is concerned with the proposal to set a lower limit on the dispersion in the angular variations of the temperature of the electromagnetic radiation by considering the process whereby photons are scattered by electrons moving in an adiabatic wave. The pregalactic phase in the development of small, adiabatic plasma and neutrino irregularities is considered, taking into account the changes in the hydrogen recombination kinetics.