Big bang nucleosynthesis (BBN) and the cosmic baryon density from cosmic microwave background anisotropies together predict a primordial Li abundance a factor of 2–3 higher than that observed in galactic halo dwarf stars. A recent analysis of Li observations in halo stars, using significantly higher surface temperature for these stars, found a higher Li plateau abundance. These results go a lon...

The heavy elements formed by neutron-capture processes have an interesting history from which we can extract useful clues to and constraints upon both the characteristics of the processes themselves and the star formation and nucleosynthesis history of Galactic matter. Of particular interest in this regard are the heavyelement compositions of extremely metal deficient stars. At metallicities [F...

I derive completely analytically the time evolution and final abundances of the light elements (up to 7Be) formed in the big-bang nucleosynthesis.This highlights an interesting physics taking place during the formation of light elements in the early universe.

Big Bang Nucleosynthesis (BBN) represents a key subject of modern cosmology since it is a powerful tool to study fundamental interactions. In the recent years, the improvement on the measurement accuracy of light primordial nu-clei abundances allowed BBN to enter in a sort of precision era. In view of this, a great theoretical effort has been devoted to make theoretical predictions comparably a...

During its early evolution, the hot, dense Universe provided a laboratory for probing fundamental physics at high energies. By studying the relics from those early epochs, such as the light elements synthesized during primordial nucleosynthesis when the Universe was only a few minutes old, and the relic, cosmic microwave photons, last scattered when the protons, alphas, and electrons (re)combin...

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

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...

We review the characteristics of nucleosynthesis in ’Hypernovae’, i.e., corecollapse supernovae with very large explosion energies ( ∼ > 10 ergs). The hypernova yields show the following characteristics: 1) The mass ratio between the complete and incomplete Si burning regions is larger in hypernovae than normal supernovae. As a result, higher energy explosions tend to produce larger [(Zn, Co, V...

We present preliminary results of stellar structure and nucleosynthesis calculations for some early stars. The study (still in progress) seeks to explore the expected chemical signatures of second generation lowand intermediate-mass stars that may have formed out of a combination of Big Bang and Pop III (Z=0) supernovae material. Although the study is incomplete at this stage, we find some impo...