Related papers: Big Bang Nucleosynthesis Calculation
We take a fresh look at the limits on the number of neutrino flavors derived from big bang nucleosynthesis. In particular, recent measurements of the \he4 abundance enable one to estimate the primordial \he4 mass fraction at $Y_p = 0.232…
We reanalyze the allowed parameters for inhomogeneous big bang nucleosynthesis in light of the WMAP constraints on the baryon-to-photon ratio and a recent measurement which has set the neutron lifetime to be 878.5 +/- 0.7 +/- 0.3 seconds.…
Standard Big Bang Nucleosynthesis (BBN) predicts the abundances of the light elements in the early universe. Even if the overall agreement with the experimental data is good, still some discrepancies exist on the relic abundances of…
We present an improved calculation of the light element abundances in the framework of Big Bang nucleosynthesis as a function of the Higgs vacuum expectation value $v$. We compare the methods of our calculation to previous literature…
A detailed analysis of primordial nucleosynthesis predictions for light element abundances is performed. Contents: 1. The standard cosmology: an overview. 2. Primordial nucleosynthesis. 3. The Born rates for n<->p reactions. 4. Finite…
We consider Big Bang Nucleosynthesis (BBN) with long lived charged massive particles. Before decaying, the long lived charged particle recombines with a light element to form a bound state like a hydrogen atom. This effect modifies the…
A brief overview of non-standard big bang nucleosynthesis (BBN) scenarios is presented. Trends and results of the light-element nucleosynthesis in BBN scenarios with small-scale or large-scale inhomogeneity, the presence of antimatter…
Four light isotopes - D, ^3He, ^4He and ^7Li - were produced by nuclear reactions a few seconds after the big bang. New measurements of ^3He in the ISM by Gloeckler and Geiss and of deuterium in high redshift hydrogen clouds by Tytler and…
We review important reactions in the big bang nucleosynthesis (BBN) model involving a long-lived negatively charged massive particle, $X^-$, which is much heavier than nucleons. This model can explain the observed $^7$Li abundances of…
Big Bang Nucleosynthesis (BBN) offers one of the most strict evidences for the Lambda-CDM cosmology at present, as well as the Cosmic Microwave Background (CMB) radiation. In this work, our main aim is to present the outcomes of our…
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…
Big Bang Nucleosynthesis (BBN) has increasingly become the tool of choice for investigating the permitted variation of fundamental constants during the earliest epochs of the Universe. Here we present a BBN calculation that has been…
We reconsider the effects of unstable particles on the production and destruction of the primordial light elements, with a view to reconciling the high primordial Li7 abundance deduced from Big Bang Nucleosynthesis (BBN), as implied by the…
We study the effect of large baryonic isocurvature perturbations on the abundance of deuterium (D) synthesized in big bang nucleosynthesis (BBN). We found that large baryonic isocurvature perturbations existing at the BBN epoch ($T\sim…
The reaction rates of the direct astrophysical capture processes $^{3}{\rm He}(\alpha, \gamma)^{7}{\rm Be}$ and $^{3}{\rm H}(\alpha,\gamma)^{7}{\rm Li}$, as well as the abundance of the $^{7}{\rm Li}$ element are estimated in the framework…
We study the big-bang nucleosynthesis (BBN) with the long-lived exotic particle, called X. If the lifetime of X is longer than \sim 0.1 sec, its decay may cause non-thermal nuclear reactions during or after the BBN, altering the predictions…
Big bang nucleosynthesis has long provided the primary determination of the cosmic baryon density $\omb h^2$, or equivalently the baryon-to-photon ratio, \eta. Recently, data on CMB anisotropies have become increasingly sensitive to \eta.…
Primordial nucleosynthesis provides a probe of the Universe during its early evolution. Given the progress exploring the constituents, structure, and recent evolution of the Universe, it is timely to review the status of Big Bang…
According to the standard models of particle physics and cosmology, there should be a background of cosmic neutrinos in the present Universe, similar to the cosmic microwave photon background. The weakness of the weak interactions renders…
An introductory review of the early evolution of the Universe relevant to the primordial synthesis of the light nuclides deuterium, helium-3, helium-4 and lithium-7. The predictions of the element abundances in the "standard", hot, big bang…