Systematic uncertainties in the light-element abundances and their evolution complicate a rigorous statistical assessment. However, using Bayesian methods we show that the following statement is robust: The predicted and measured abundances are consistent with 95% credibility only if the baryon-to-photon ratio is between 2×10-10 and 6.5×10-10 and the number of light neutrino species is less than 3.9. Our analysis suggests that the 4He abundance may have been systematically underestimated.
Physical Review Letters
- Pub Date:
- November 1995
- Origin formation and abundances of the elements;
- 7 pages, LaTeX(2.09), 6 postscript figures (attached). A postscript version with figures can be found at ftp://astro.uchicago.edu/pub/astro/copi/assessing_BBN . (See the README file for details)