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Neutron diffusion and nucleosynthesis

  1. Jun 17, 2005 #1


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    Title: Neutron Diffusion and Nucleosynthesis in an Inhomogeneous Big Bang Model
    Authors: Juan F. Lara
    Comments: accepted for publication in Physical Review D

    This article presents an original code for Big Bang Nucleosynthesis in a baryon inhomogeneous model of the universe. In this code neutron diffusion between high and low baryon density regions is calculated simultaneously with the nuclear reactions and weak decays that compose the nucleosynthesis process. The size of the model determines the time when neutron diffusion becomes significant. This article describes in detail how the time of neutron diffusion relative to the time of nucleosynthesis affects the final abundances of He4, deuterium and Li7. These results will be compared with the most recent observational constraints of He4, deuterium and Li7. This inhomogeneous model has He4 and deuterium constraints in concordance for baryon to photon ratio eta = (4.3 - 12.3) X 10^{-10} Li7 constraints are brought into concordance with the other isotope constraints by including a depletion factor as high as 5.9. These ranges for the baryon to photon ratio and for the depletion factor are larger than the ranges from a Standard Big Bang Nucleosynthesis model.
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  3. Jun 17, 2005 #2


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    Does that mean the standard BBN model has to be baryon homogeneous?

  4. Jun 17, 2005 #3


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    I think yes, but I am not sure. The universe is homogeneous after inflation. Why should it be 'baryon inhomogeneous'?
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