Inhomogeneous Big Bang Nucleosynthesis Revisited

We reanalyze the allowed parameters for inhomogeneous big bang nucleosynthesis in light of the WMAP constraints on the baryon-to-photon ratio and a recent measurement which has set the neutron lifetime to be 878.5 +/- 0.7 +/- 0.3 seconds. For a set baryon-to-photon ratio the new lifetime reduces the mass fraction of He4 by 0.0015 but does not significantly change the abundances of other isotopes. This enlarges the region of concordance between He4 and deuterium in the parameter space of the baryon-to-photon ratio and the IBBN distance scale. The Li7 abundance can be brought into concordance with observed He4 and deuterium abundances by using depletion factors as high as 9.3. The WMAP constraints, however, severely limit the allowed comoving (T = 100 GK) inhomogeneity distance scale to (1.3 - 2.6)x10^5 cm.