After a brief review of the cosmological lithium problem, we report a few recent attempts to find theoretical solutions by our group at Texas A&M University (Commerce & College Station). We will discuss our studies on the theoretical description of electron screening, the possible existence of parallel universes of dark matter, and the use of non-extensive statistics during the Big Bang nucleos...

Context. The Scorpius-Centaurus association is the most-nearby group of massive and young stars. As nuclear-fusion products are ejected by massive stars and supernovae into the surrounding interstellar medium, the search for characteristic γ-rays from radioactivity is one way to probe the history of activity of such nearby massive stars on a My time scale through their nucleosynthesis. 26Al dec...

The heavy elements formed by neutron capture processes have an interesting history from which we can extract useful clues to and constraints upon the star formation and nucleosynthesis history of Galactic matter. Of particular interest are the heavy element compositions of extremely metal-deficient stars. At metallicities [Fe/H] ≤ -2.5, stellar abundance data (for both halo field stars and glob...

Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. In a companion paper Detmold et al. [Phys. Rev. D 90, 114506 (2014)], lattice field theory methods are used to show...

Context. Primordial molecules were formed during the Dark Ages, i.e. the time between recombination and reionization in the early Universe. They were the constitutents of the first proto-stellar clouds. Standard Big Bang nucleosynthesis predicts the abundances of hydrogen, helium, lithium, beryllium, and their isotopes in the early Universe. Heavier nuclei such as carbon, nitrogen, or oxygen ar...

We present a review of the main phases of stellar evolution with particular emphasis on the nucleosynthesis and mixing mechanisms in low-and intermediate-mass stars. In addition to explicit studies of the eeects of the rst, second and third dredge-up, we also discuss cool bottom processing and hot bottom burning. In recent years a wealth of new abundance data has been obtained, both from stella...

Light element (Li, Li and Be) depletion isochrones for halo stars have been calculated with standard stellar evolution models. These models include the latest available opacities and are computed through the sub-giant branch. If Li is not produced in appreciable amounts by stellar flares, then the detection of Li in HD 84937 by Smith, Lambert & Nissen (1993) is compatible with standard stellar ...

Recent observations of heavy elements produced by rapid neutron capture (r-process) in the halo have shown a striking and unexpected behavior: within a single star, the relative abundances of r-process elements heavier than Eu are the same as the same as those of solar system matter, while across stars with similar metallicity Fe/H, the r/Fe ratio varies over two orders of magnitude. In this pa...

We report the abundances of neutron-capture elements in eight carbon-rich, metal-poor ( 2:7 1⁄2Fe=H 1:9) stars observed with the Subaru Telescope High Dispersion Spectrograph. The derived abundance patterns indicate that the neutron-capture elements in these objects primarily originated from s-process nucleosynthesis, although the [Ba/Eu] abundance ratios in some objects are lower than that of ...