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J.F. Lara (Department of Physics and Astronomy, Clemson University)
Recent measurements by Kirkman et al ( 2003 ) of deuterium from Quasi-Stellar Objects correspond to a baryon density \OmegaB h2 = 0.0214 ± 0.0020 in the Standard Big Bang Nucleosynthesis ( SBBN ) model. Measurements by Ryan et al ( 2000 ) of 7Li in metal poor stars however have set a conservative uppper limit of \OmegaB h2 \le 0.017 in the SBBN model. Kajino ( 2002 ) has proposed that a cylindrically symmetric baryon Inhomogeneous Big Bang Nucleosynthesis ( IBBN ) model with lepton asymmetry could bring the deuterium and 7Li abundances into agreement regarding \OmegaB h2. This talk is the beginning of a project to test this proposal. Parameters that define IBBN models include the geometry of the baryon distribution, the ratio between high and low baryon densities, the size of the model ri, and the baryon to photon ratio \eta. We will discuss the contour maps of deuterium and 7Li for cylindrically and spherically symmetric IBBN models in the parameter space defined by ri and \eta. The values of the remaining parameters are taken from Orito et al ( 1997 ). In Orito et al ( 1997 ), concordance between the observations of deuterium and 7Li current at that time was found for cylindrically symmetric models. The more recent observations however place stricter constraints on permitted values of IBBN parameters, and we find no region of concordance in the maps featured in this talk.. In future research, the IBBN parameters will be futher varied to find values that will produce regions of concordance, or examples of near concordance. We will also fully implement neutrino degeneracy in our IBBN models. Lepton asymmetry of the neutrinos might alter the contours to bring about concordance. The project has funding from the Clemson University Department of Physics and Astronomy.
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The author(s) of this abstract have provided an email address for comments about the abstract: ljuan@clemson.edu
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Bulletin of the American Astronomical Society, 35#5
© 2003. The American Astronomical Soceity.