Does inhomogeneous big bang nucleosynthesis produce an inhomogeneous element distribution today?

Abstract

Inhomogeneous big bang nucleosynthesis (BBN) produces a spatially inhomogeneous distribution of element abundances at $T\sim 10^9$ K, but subsequent element diffusion will tend to erase these inhomogeneities. We calculate the cosmological comoving diffusion length for the BBN elements. This diffusion length is limited by atomic scattering and is therefore dominated by diffusion when the atoms are neutral, between the redshifts of recombination and reionization. We find that the comoving diffusion length today is $d_{com}\approx 70$ pc for all of the elements of interest except ${}^7$Li, for which $d_{com}$ is an order of magnitude smaller because ${}^7$Li remains ionized throughout the relevant epoch. This comoving diffusion length corresponds to a substellar baryonic mass scale and is roughly equal to the horizon scale at BBN. These results lend support to the possibility that inhomogeneities on scales larger than the horizon at BBN could lead to a spatially inhomogeneous distribution of elements today, while purely subhorizon fluctuations at BBN can result only in a homogeneous element distribution at present.

arXiv comment5 pages, no figures

References in corpus (26)

• The Primordial Lithium Problem
• Big-Bang Nucleosynthesis After Planck
• On Possible Variation in the Cosmological Baryon Fraction
• Matter temperature after cosmological recombination
• Dynamic Localised Turbulent Diffusion and its Impact on the Galactic Ecosystem
• Big Bang Nucleosynthesis with Matter--Antimatter Domains
• Big Bang Nucleosynthesis with an Inhomogeneous Primordial Magnetic Field Strength
• Constraining Antimatter Domains in the Early Universe with Big Bang Nucleosynthesis
• Inhomogeneous Big Bang Nucleosynthesis Revisited
• Affleck-Dine Baryogenesis and heavy elements production from Inhomogeneous Big Bang Nucleosynthesis
• Time of primordial Be-7 conversion into Li-7, energy release and doublet of narrow cosmological neutrino lines
• Ionizing radiation from hydrogen recombination strongly suppresses the lithium scattering signature in the CMB
• Limits on Cosmic Matter--Antimatter Domains from Big Bang Nucleosynthesis
• Antimatter Regions in the Early Universe and Big Bang Nucleosynthesis
• Stellar Signatures of Inhomogeneous Big Bang Nucleosynthesis
• Chemical separation of primordial Li${}^{+}$ during structure formation caused by nanogauss magnetic field
• Varying leptonic chemical potentials and spatial variation of primordial deuterium at high z
• Constraining Density Fluctuations with Big Bang Nucleosynthesis in the Era of Precision Cosmology
• BBN constraints on dark radiation isocurvature
• Large Scale Baryon Isocurvature Inhomogeneities
• Inhomogeneous Neutrino Degeneracy and Big Bang Nucleosynthesis
• A linear programming approach to inhomogeneous primordial nucleosynthesis
• Initial Li Abundances in the Protogalaxy and Globular Clusters Based upon the Chemical Separation and Hierarchical Structure Formation
• Multiple Main Sequence of Globular Clusters as a Result of Inhomogeneous Big Bang Nucleosynthesis
• Big Bang Nucleosynthesis with Gaussian Inhomogeneous Neutrino Degeneracy
• Helium diffusion during formation of the first galaxies