Geometrical Effects of Baryon Density Inhomogeneities on Primordial Nucleosynthesis
Abstract
We discuss effects of fluctuation geometry on primordial nucleosynthesis. For the first time we consider condensed cylinder and cylindricalshell fluctuation geometries in addition to condensed spheres and spherical shells. We find that a cylindrical shell geometry might allow for an appreciably higher baryonic fraction of the closure density (Ω_{b}h^{2}_{50}<~0.2) than that allowed in spherical inhomogeneous or standard homogeneous big bang models. This result, which is contrary to those of some other recent studies, is due to both geometry and recently revised estimates of the uncertainties in the observationally inferred primordial lightelement abundances. We also find that inhomogeneous primordial nucleosynthesis in the cylindrical shell geometry can lead to significant Be and B production. In particular, this geometry produces a primordial beryllium abundance as high as [Be] = 12 + log (Be/H) ~ 3 while still satisfying all of the lightelement abundance constraints.
 Publication:

The Astrophysical Journal
 Pub Date:
 October 1997
 DOI:
 10.1086/304716
 arXiv:
 arXiv:astroph/9609130
 Bibcode:
 1997ApJ...488..515O
 Keywords:

 Cosmology: Theory;
 Cosmology: Dark Matter;
 Cosmology: Early Universe;
 Nuclear Reactions;
 Nucleosynthesis;
 Abundances;
 Astrophysics
 EPrint:
 Latex, 20 pages + 11 figures(not included). Entire ps file with embedded figures available via anonymous ftp at ftp://genova.mtk.nao.ac.jp/pub/prepri/bbgeomet.ps.gz