Relic neutrino decoupling including flavour oscillations

By G. Mangano, G. Miele, S. Pastor, T. Pinto, O. Pisanti, P. Serpico. 2005

718 citations recorded by the source corpus.

Abstract In the early universe, neutrinos are slightly coupled when electron–positron pairs annihilate transferring their entropy to photons. This process originates non-thermal distortions on the neutrino spectra which depend on neutrino flavour, larger for ν e than for ν μ or ν τ . We study the effect of three-neutrino flavour oscillations on the process of neutrino decoupling by solving the momentum-dependent kinetic equations for the neutrino spectra. We find that oscillations do not essentially modify the total change in the neutrino energy density, giving N eff = 3.046 in terms of the effective number of neutrinos, while the small effect over the production of primordial 4 He is increased by O ( 20 % ) , up to 2.1 × 10 −4 . These results are stable within the presently favoured region of neutrino mixing parameters.

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/de7a2b690675b89d85c87078fee5cd10cdce119d

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In Nuclear and High Energy Physics

Citations in the corpus

The effects of QCD equation of state on the relic density of WIMP dark matter (2015, neutral): “046 [50].”
Neutrino decoupling beyond the Standard Model: CMB constraints on the Dark Matter mass with a fast and precise Neff evaluation (2018, methodology): “The difference between our result and that of Reference [5] is mainly a consequence of our inability to account for non-thermal corrections to the neutrino distribution function (but the small difference shows that they are indeed small, δρν/ρν < 1 % [5, 6]).”
Cosmology with a very light Lμ − Lτ gauge boson (2019, background): “045 [35, 36] is slightly larger than 3 because of the entropy transferred to the neutrinos through e+e− annihilations, the non-instantaneous nature of neutrino decoupling, finite temperature corrections, and neutrino oscillations [35–38].”
MeV-scale reheating temperature and thermalization of oscillating neutrinos by radiative and hadronic decays of massive particles (2019, background): “[18] G.”
Thermalisation of light sterile neutrinos in the early universe (2012, background): “046, slightly exceeds 3 because of e+e− annihilation providing residual neutrino heating [15].”