Cosmological scalar fields and Big-Bang nucleosynthesis

Cosmological Nucleosynthesis in the Big-Bang and Supernovae

Recent observation of the power spectrum of Cosmic Microwave Background (CMB) Radiation has exhibited that the flat cosmology is most likely. This suggests too large universal baryon-density parameter Ωbh2 ≈ 0.022 ∼ 0.030 to accept a theoretical prediction, Ωbh2 ≤ 0.017, in the homogeneous Big-Bang model for primordial nucleosynthesis. Theoretical upper limit arises from the sever constraints o...

Big Bang Nucleosynthesis

Big Bang Nucleosynthesis: Reprise

Recent observational and theoretical developments concerning the primordial synthesis of the light elements are reviewed, and the implications for dark matter mentioned.

Assessing Big-Bang nucleosynthesis.

Systematic uncertainties in the light-element abundances and their evolution make a rigorous statistical assessment difficult. 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 and 6.5× 10 and the number of light neutrino species is less tha...

Big Bang Nucleosynthesis Calculation

I review standard big bang nucleosynthesis and some versions of nonstandard BBN. The abundances of the primordial isotopes D, He-3, and Li-7 produced in standard BBN can be calculated as a function of the baryon density with an accuracy of about 10%. For He-4 the accuracy is better than 1%. The calculated abundances agree fairly well with observations, but the baryon density of the universe can...