Abstract

The cosmic neutrinos background (CNB) comprises primordial neutrinos that were decoupled when the Universe was very young. Its detection is complicated, especially if we take into account neutrino mass and a possible breaking of Lorentz invariance at high energy, but has a fundamental relevance to studying the Big Bang. In this paper, we will see that a Lorentz violation does not produce important modification, but the mass does. We will show how the neutrino current velocity, with respect to the comobile system of the universe expansion, is of the order of 1065 km/s, much less than the velocity of light. Besides, we will see that the neutrino distribution is complex due to planetary motion. This prediction differs totally from the usual massless case, where we would get a correction similar to the dipolar moment of the CMB. © 2008 World Scientific Publishing Company.