Apart from cosmological hydrogen and helium, chemical elements in the Universe are produced stars, during both quiescent explosive phases. The Sun distribution witnesses pollution already extinct stellar generations at different epochs before Solar System formation. two major nucleosynthesis processes responsible for formation of heavier than iron slow neutron capture process (the s-process) ra...

Explosive nucleosynthesis is a combination of the nuclear physics of thermonuclear reactions, and the hydrodynamics of the plasma in which the reactions occur. It depends upon the initial conditions—the stellar evolution up to the explosive instability, and the nature of the explosion mechanism. Some key issues for explosive nucleosynthesis are the interaction of burning with hydrodynamics, the...

Big Bang Nucleosynthesis (BBN), along with the cosmic background radiation and the Hubble expansion, is one of the pillars of the standard, hot, big bang cosmology since the primordial synthesis of the light nuclides (D, He, He, Li) must have occurred during the early evolution of a universe described by this model. The overall consistency between the predicted and observed abundances of the li...

We investigate the effect of duplicity on stellar yields of carbon, nitrogen, and oxygen. Populations of single and binary stars are modelled and the yields calculated for the whole population. The effects of explosive nucleosynthesis in novae and supernovae are included but by artificially removing these effects from our populations we determine the influence of a binary companion on asymptoti...

The importance of the Big Bang Nucleosynthesis (BBN) as a unique tool for studying neutrino properties is discussed, and the recent steps towards a self-consistent and robust handling of the weak reaction decoupling from the thermal bath as well as of the neutrino reheating following the e − e− annihilation are summarized. We also emphasize the important role of the Cosmic Microwave Background ...

Big Bang Nucleosynthesis is the theory of the production of the light element isotopes of D, 3He, 4He, and 7Li. After a brief review of the essential elements of the standard Big Bang model at a temperature of about 1 MeV, the theoretical input and predictions of BBN are discussed. The theory is tested by the observational determinations of the light element abundances and the current status of...

In this review, we discuss the impact of s-process nucleosynthesis in asymptotic giant branch stars on enrichment heavy elements. We review main steps made subject last 40 years and importance modelling evolution abundances such elements our Milky Way. From comparison between model results observations, can impose strong constraints stellar nucleosynthesis, as well

A comprehensive study of the effect of an unstable tau neutrino on primordial nucleosynthesis is presented. The standard code for nucleosynthesis is modified to allow for a massive decaying tau neutrino whose daughter products include neutrinos, photons, e pairs, and/or noninteracting (sterile) daughter products. Tau-neutrino decays influence primordial nucleosynthesis in three distinct ways: (...

The recent determination of the baryon-to-photon ratio from WMAP data by Spergel et al. (2003) allows one to fix with unprecedented precision the primordial abundances of the light elements D, He, He and Li in the framework of the standard model of big bang nucleosynthesis. We adopt these primordial abundances and discuss the implications for Galactic chemical evolution, stellar evolution and n...