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Neutrino Heating in an Inhomogeneous Big Bang Nucleosynthesis Model

J. F. Lara
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Abstract

The effect of the heating of neutrinos by scattering with electrons and positrons and by e-e+ annihilation on nucleosynthesis is calculated for a spherically symmetric baryon inhomogeneous model of the universe. The model has a high baryon density core and a low density outer region. The heating effect is calculated by solving the Boltzmann Transport Equation for the distribution functions of electron and muon/tau neutrinos. For a range of baryon-to-photon ratio = [ 0, 1.5 ] x 10^-10 and distance scale = [ 10^2, 10^8 ] cm the heating effect increases the mass fraction of He4 by a range of [1, 2] x 10^-4. The change of the value of the mass fraction of He4 appears similiar to the change caused by an upward shift in the value of the baryon-to-photon ratio. But the change to deuterium is a decrease in abundance ratio Y(d)/Y(p) on the order of 10^-3, one order less than the decrease due to a shift in baryon-to-photon ratio.

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J. F. Lara. 2001-07-18. Neutrino Heating in an Inhomogeneous Big Bang Nucleosynthesis Model. https://doi.org/10.1063/1.1419579

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