相关论文: LiBeB and Big Bang Nucleosynthesis
Recently it is reported that there is the discrepancy between big bang nucleosynthesis theory and observations (BBN crisis). We show that BBN predictions agree with the primordial abundances of light elements, He4, D, He3 and Li7 inferred…
We derive constraints from standard (with $N_\nu = 3$) BBN arising solely from two cosmologically produced nuclides, \he4 and \li7, from which the extrapolation to primordial abundances is straightforward. The abundances of D and \he3 are…
Big Bang Nucleosynthesis (BBN) is the synthesis of the light nuclei, Deuterium, He3, He4 and Li7, during the first few minutes of the universe. This review concentrates on recent improvements in the measurement of the primordial (after BBN,…
In the standard hot big bang nucleosynthesis (BBN) model the primordial abundances of H, H2, He3, He4, and Li7, fix the baryon density of the universe, $\Omega_b$, via the baryon-to-photon ratio, $\eta$, for a given Hubble parameter. Recent…
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…
The primordial abundances of Deuterium, he4, and li7 are crucial to determination of the baryon density of the Universe in the framework of standard Big Bang nucleosynthesis (BBN). li6 which is only produced in tiny quantities and it is…
Recent determinations of the deuterium abundance, $^2$H/H, in high redshift Lyman limit hydrogen clouds challenge the usual picture of primordial nucleosynthesis based on \lq\lq concordance\rq\rq\ of the calculated light element ($^2$H,…
Big Bang Nucleosynthesis is the theory of the production of the the light element isotopes of D, He3, He4, and Li7. After a brief review of the essential elements of the standard Big Bang model at a temperature of about 1 MeV, the…
Big Bang Nucleosynthesis (BBN), along with the cosmic background radiation and the Hubble expansion, is one of the pillars ofthe standard, hot, big bang cosmology since the primordial synthesis of the light nuclides (D, $^3$He, $^4$He,…
The standard model of primordial nucleosynthesis by the Big Bang as selected by the WMAP-based estimate of the baryon density ($\Omega_bh^2$) predicts an abundance of $^7$Li that is a factor of three greater than the generally reported…
The predictions of Standard Big Bang Nucleosynthesis are summarized and compared with observations of abundances of helium in HII regions, deuterium in quasar absorbers, deuterium and helium-3 in the Galaxy, and lithium in metal-poor stars.…
During its hot, dense, early evolution the Universe was a primordial nuclear reactor, synthesizing the light nuclides D, 3He, 4He and 7Li in the first thousand seconds. The presently observed abundances of these relic nuclides provide a…
I present a review of Big Bang Nucleosynthesis, concentrating on the statistical analysis of theoretical uncertainties, and on systematic errors in observed abundances. Both have important implications for constraints on the amount of…
Assuming the best numerical value for the cosmic baryonic density and the existence of three neutrino flavors, standard big bang nucleosynthesis is a parameter-free model. It is important to assess if the observed primordial abundances can…
The concordance of standard big bang nucleosynthesis theory and the related observations of the light element isotopes (including some new higher \he4 abundances) will be reviewed. Implications of BBN on chemical evolution, dark matter and…
The Big Bang Nucleosynthesis (BBN) model is a cornerstone for the understanding of the evolution of the early universe, making seminal predictions that are in outstanding agreement with the present observation of light element abundances in…
Thanks to the accurate determination of the baryon density of the universe by the recent cosmic microwave background experiments, updated predictions of the standard model of Big Bang nucleosynthesis now yield the initial abundance of the…
Light element nucleosynthesis is an important chapter of nuclear astrophysics. Specifically, the rare and fragile light nuclei Lithium, Beryllium and Boron (LiBeB) are not generated in the normal course of stellar nucleosynthesis (except…
There is continued interest in the possibility that big bang nucleosynthesis may produce significant quantities of Be and B. In this paper we reevaluate the primordial abundances taking into account uncertainties in reactions rates. We…
Big-bang nucleosynthesis (BBN) describes the production of the lightest nuclides via a dynamic interplay among the four fundamental forces during the first seconds of cosmic time. We briefly overview the essentials of this physics, and…