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arXiv · 1409.2964

Fermi-Boltzmann statistics of neutrinos and relativistic effective degrees of freedom

Jun Iizuka·Teruyuki Kitabayashi
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Abstract

We investigate the effect of the presence of non-pure fermionic neutrinos on the relativistic effective degrees of freedom in the early universe. The statistics of neutrinos is transformed continuously from Fermi-Dirac to Maxwell-Boltzmann statistics. We find that the relativistic degrees of freedom decreases with the deviation from pure Fermi-Dirac statistics of neutrinos if there are constant and large lepton asymmetries. Additionally, we confirm that the change of the statistics of neutrinos from Fermi-Dirac to Maxwell-Boltzmann is not sufficient to cover the excess of the effective number of neutrinos.

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Jun Iizuka, Teruyuki Kitabayashi. 2014-11-22. Fermi-Boltzmann statistics of neutrinos and relativistic effective degrees of freedom. https://doi.org/10.1142/s0217732315500030

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