Related papers: Lithium-6 : Evolution from Big Bang to Present
Observations of low-metallicity halo stars have revealed a puzzling result: the abundance of \li7 in these stars is at least three times lower than their predicted primordial abundance. It is unclear whether the cause of this disagreement…
We present a critical analysis of the nature of the so-called Li-rich RGB stars. For a majority of the stars, we have used Hipparcos parallaxes to determine masses and evolutionary states by comparing their position on the…
Oxygen is a much better evolutionary index than iron to describe the history of Lithium-Beryllium-Boron (LiBeB) since it is the main producer of these light elements at least in the early Galaxy. The O-Fe relation is crucial to the…
The discovery of the Spite plateau in the abundances of 7Li for metal-poor stars led to the determination of an observationally deduced primordial lithium abundance. However, after the success of the Wilkinson Microwave Anisotropy Probe…
From a recent re-analysis of the available data, Be and B Galactic evolution appears to show evidence for a two-slope behaviour with respect to O. The inferred Be/O abundance ratio in halo stars is constant at very low metallicity (primary…
To understand better the early galactic production of Li, Be, and B by cosmic ray spallation and fusion reactions, the dependence of these production rates on cosmic ray models and model parameters is examined. The sensitivity of elemental…
We have determined Li abundances in 55 metal-poor (3.6 < [Fe/H] < -0.7) stars with extreme orbital kinematics. We find the Li abundance in the Li-plateau stars and examine its decrease in low-temperature, low-mass stars. The Li observations…
The single stable isotope of beryllium is a pure product of cosmic-ray spallation in the ISM. Assuming that the cosmic-rays are globally transported across the Galaxy, the beryllium production should be a widespread process and its…
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 amount of deuterium relative to hydrogen (D/H) in clouds with close to primordial abundance seen at high redshift in the spectra of distant quasars currently provides the best estimate of the baryonic density of the Universe. The first…
The origin of lithium (Li) and its production process have long been an unsettled question in cosmology and astrophysics. Candidates environments of Li production events or sites suggested by previous studies include big bang…
Deuterium plays a crucial role in testing big-bang nucleosynthesis. Its chemical evolution, while simple (it is burned to $^3$He), is intertwined with the more complicated evolution of $^3$He. Gloeckler \& Geiss' new measurement of the…
The products of primordial nucleosynthesis and the cosmic microwave background (CMB) photons are relics from the early evolution of the Universe whose observations probe the standard model of cosmology and provide windows on new physics…
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…
The light elements beryllium (Be; $Z=4$) and boron (B; $Z=5$) are mainly produced by spallation reactions between cosmic rays and carbon (C; $Z=6$), nitrogen (N; $Z=7$), and oxygen (O; $Z=8$) nuclei. Only traces of Be or B would have been…
Lithium abundances are presented for 91 dwarf and subgiant stars in the Galactic bulge. The analysis is based on line synthesis of the 7Li line at 6707 {\AA} in high-resolution spectra obtained during gravitational microlensing events, when…
The current status of big bang nucleosynthesis is summarized. Particular attention is paid to recent observations of He4 and Li7 and their systematic uncertainties. Be and B are also discussed in connection to recent Li7 observations and…
We compute the big bang nucleosynthesis limit on the number of light neutrino degrees of freedom in a model-independent likelihood analysis based on the abundances of He4 and Li7. We use the two-dimensional likelihood functions to…
We present a non-local thermodynamic equilibrium abundance analysis of the resonance doublet Li I at 6707.8 A for 55 Galactic F and G supergiants and bright giants. The derived lithium abundances log \epsilon(Li) may be considered in three…
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,…