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Cosmological Neutrino Background Revisited

Nickolay Y. Gnedin·Oleg Y. Gnedin
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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%.

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Nickolay Y. Gnedin, Oleg Y. Gnedin. 1999-10-15. Cosmological Neutrino Background Revisited. https://doi.org/10.1086/306469

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