Cosmological Neutrino Background Revisited
Astrophysics
2009-10-30 v4
Abstract
We solve the Boltzmann equation for cosmological neutrinos around the epoch of the electron-positron annihilation in order to verify the freeze-out approximation and to compute accurately the cosmological neutrino distribution function. We find the radiation energy density to be about 0.3% higher than the one predicted by the freeze-out approximation. As a result, the spectrum of the Cosmic Microwave Background anisotropies changes by 0.3-05%, depending on the angular scale, and the amplitude of the mass fluctuations on scales below about 100 h^{-1} Mpc decreases by about 0.2-0.3%.
Cite
@article{arxiv.astro-ph/9712199,
title = {Cosmological Neutrino Background Revisited},
author = {Nickolay Y. Gnedin and Oleg Y. Gnedin},
journal= {arXiv preprint arXiv:astro-ph/9712199},
year = {2009}
}
Comments
An error is corrected, figure revised; submitted to ApJ