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arXiv · hep-ph/9703315

Nonequilibrium Corrections to the Spectra of Massless Neutrinos in the Early Universe

A. D. Dolgov·S. H. Hansen·D. V. Semikoz
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Abstract

Distortion of the equilibrium spectra of cosmic neutrinos due to interaction with hotter electrons and positrons in the primeval cosmic plasma is considered. The set of integro-differential kinetic equations for neutrinos is accurately numerically solved. The relative corrections to neutrino energy densities are approximately 0.9% for $ν_e$ and 0.4% for $ν_μ$ and $ν_τ$. This effect results in $1.4 \cdot 10^{-4}$ increase in the primordial $^4 He$ abundance.

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A. D. Dolgov, S. H. Hansen, D. V. Semikoz. 1997-03-13. Nonequilibrium Corrections to the Spectra of Massless Neutrinos in the Early Universe. https://doi.org/10.1016/s0550-3213(97)00479-3

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