On the sign of the neutrino asymmetry induced by active-sterile neutrino oscillations in the early Universe

Abstract

We deal with the problem of the final sign of the neutrino asymmetry generated by active-sterile neutrino oscillations in the Early Universe solving the full momentum dependent quantum kinetic equations. We study the parameter region $10^{-2}\stackrel{<}{\sim }|\delta m^2|/e{V}^2\le 10^3$. For a large range of ${\sin }^{2}2{\theta }_0$ values the sign of the neutrino asymmetry is fixed and does not oscillate. For values of mixing parameters in the region $10^{-6}\stackrel{<}{\sim }{\sin }^{2}2{\theta }_0\stackrel{<}{\sim }3\times 10^{-4}({\mathrm{eV}}^2/|\delta m^2|)$, the neutrino asymmetry appears to undergo rapid oscillations during the period where the exponential growth occurs. Our numerical results indicate that the oscillations are able to change the neutrino asymmetry sign. The sensitivity of the solutions and in particular of the final sign of lepton number to small changes in the initial conditions depends whether the number of oscillations is high enough. It is however not possible to conclude whether this effect is induced by the presence of a numerical error or is an intrinsic feature. As the amplitude of the statistical fluctuations is much lower than the numerical error, our numerical analysis cannot demonstrate the possibility of a chaotical generation of lepton domains. In any case this possibility is confined to a special region in the space of mixing parameters and it cannot spoil the compatibility of the ${\nu }_{\mu }\leftrightarrow {\nu }_s$ solution to the neutrino atmospheric data obtained assuming a small mixing of the ${\nu }_s$ with an $\mathrm{eV}-\tau$ neutrino.

arXiv commentTypo's corrected, accepted for publication in Phys.Rev.D

References in corpus (13)

• Large neutrino asymmetries from neutrino oscillations
• Reconciling sterile neutrinos with big bang nucleosynthesis
• Studies of neutrino asymmetries generated by ordinary-sterile neutrino oscillations in the early universe and implications for big bang nucleosynthesis bounds
• Relic neutrino asymmetry evolution from first principles
• Chaotic Amplification of Neutrino Chemical Potentials by Neutrino Oscillations in Big Bang Nucleosynthesis
• The exact parity symmetric model and big bang nucleosynthesis
• How neutrino oscillations can induce an effective neutrino number of less than 3 during Big Bang Nucleosynthesis
• Leptonic Domains in the Early Universe and Their Implications
• Relic neutrino asymmetries and big bang nucleosynthesis in a four neutrino model
• Neutrino degeneracy effect on neutrino oscillations and primordial helium yield
• Implications of mirror neutrinos for early universe cosmology
• Implications of the ${\nu }_{\mu }\to {\nu }_s$ solution to the atmospheric neutrino anomaly for early Universe cosmology
• On chaoticity of the amplification of the neutrino asymmetry in the early universe

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