Related papers: Primordial Nucleosynthesis
The dual origin of population II Li7, in both big bang nucleosynthesis and galactic cosmic-ray nucleosynthesis is discussed. It is argued that with additional Li6 data, stringent limits on the degree of Li7 depletion can be obtained. Li7…
In the standard Big-Bang nucleosynthesis (BBN) model, the primordial $^7$Li abundance is overestimated by about a factor of 2--3 comparing to the astronomical observations, so called the pending cosmological lithium problem. The…
Standard Big Bang Nucleosynthesis at the baryon density determined by the microwave anisotropy spectrum predicts an excess of \li7 compared to observations by a factor of 4-5. In contrast, BBN predictions for D/H are somewhat below (but…
We update the Big Bang Nucleosynthesis (BBN) calculations on the basis of the recent NACRE compilation of reaction rates. In particular, we calculate the uncertainties related to the nuclear reaction rates on the abundances of 7Li and…
The WMAP satellite, devoted to the observations of the anisotropies of the Cosmic Microwave Background (CMB) radiation, has recently provided a determination of the baryonic density of the Universe with unprecedented precision. Using this,…
We present updated and improved Big Bang Nucleosynthesis (BBN) constraints on heavy, long-lived beyond the Standard Model (BSM) relics $\phi$ decaying into pairs of Standard Model particles, covering a comprehensive set of two-body decay…
We discuss nuclear reactions which could play a role in Big Bang Nucleosynthesis (BBN). Most of these reactions involve lithium and beryllium isotopes and the rates for some of these have not previously been included in BBN calculations.…
We evaluate abundance anomalies generated in patches of the universe where the baryon-to-photon ratio was locally enhanced by possibly many orders of magnitude in the range $\eta = 10^{-10} - 10^{-1}$. Our study is motivated by the possible…
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…
The light elements up to 7Li were produced by the Standard Big Bang nucleosynthesis (SBBN) in the early universe assuming standard conditions. All observed primordial abundances of these light elements match very well the predicted ones by…
Big-bang nucleosynthesis (BBN) probes the cosmic mass-energy density at temperatures $\sim 10$ MeV to $\sim 100$ keV. Here, we consider the effect of a cosmic matter-like species that is non-relativistic and pressureless during BBN. Such a…
We analyze the effect of variation of fundamental couplings and mass scales on primordial nucleosynthesis in a systematic way. The first step establishes the response of primordial element abundances to the variation of a large number of…
A new upper limit on the amplitude of primordial magnetic field (PMF) is derived by a comparison between a calculation of elemental abundances in big bang nucleosynthesis (BBN) model and the latest observational constraints on the…
The ability to now make measurements of Be and B as well as put constraints on \lisix\ abundances in metal-poor stars has led to a detailed reexamination of Big Bang Nucleosynthesis in the $A\groughly6$ regime. The nuclear reaction network…
$f(R)$ gravity is one of the serious alternatives of general relativity having a large range of astronomical consequences. In this work, we study Big Bang Nucleosynthesis (BBN) in $f(R)$ gravity theory. We consider modification to gravity…
We present new Big Bang Nucleosynthesis (BBN) limits on the cosmic expansion rate or relativistic energy density, quantified via the number $N_\nu$ of equivalent neutrino species. We use the latest light element observations, neutron mean…
The cosmological abundance of nucleons determined from considerations of Big Bang nucleosynthesis allegedly provides compelling evidence for non-nucleonic dark matter. Recent developments in measurements of primordial light element…
Oscillations between ordinary and sterile neutrinos can generate large neutrino asymmetries in the early universe. These asymmetries can significantly affect big bang nucleosynthesis (BBN) through modification of nuclear reaction rates. We…
Nowadays, the Cosmic Microwave Background (CMB) anisotropies studies accurately determine the baryon fraction omega_b, showing an overall and striking agreement with previous determinations of omega_b obtained from Big Bang Nucleosynthesis…
A new evaluation of the constraint on the number of light neutrino species (N_nu) from big bang nucleosynthesis suggests a discrepancy between the predicted light element abundances and those inferred from observations, unless the inferred…