Related papers: Primordial Nucleosynthesis: Accurate Predictions
Primordial nucleosynthesis is an observational cornerstone of the Hot Big Bang model and a sensitive probe of physics beyond the standard model. Its success has been limited by the so-called Lithium problem, for which many solutions have…
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…
The apparent discrepancy between abundances of light nuclides predicted by the standard Big-Bang and observational data is explained, by assuming the presence of metastable H dibaryons at the nucleosynthesis era. These dibaryons could be…
Recently we presented a simple method for determining the correlated uncertainties of the light element abundances expected from big bang nucleosynthesis, which avoids the need for lengthy Monte Carlo simulations. We now extend this…
We study the effect of neutrino degeneracy on primordial nucleosynthesis in a universe in which the cosmological scale factor evolves linearly with time. The degeneracy parameter of electron type neutrinos ($\xi_e$) determines the $n/p$…
Big bang nucleosynthesis (BBN), an epoch of primordial nuclear transformations in the expanding Universe, has left an observable imprint in the abundances of light elements. Precision observations of such abundances, combined with…
To elucidate the significance of the effect of systematic uncertainties in light element abundance estimates on cosmological bounds derivable from Big Bang Nucleosynthesis (BBN) we present tables giving bounds on $\Omega_{baryon}$ and…
In the standard hot big bang model, the expansion of the early universe is given by the Friedmann equation with an energy density dominated by relativistic particles. Since in a variety of models this equation is altered, we introduce…
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…
Motivated by the recent measurement of the primeval abundance of deuterium, we re-examine the nuclear inputs to big-bang nucleosynthesis (BBN). Using Monte-Carlo realization of the nuclear cross-section data to directly estimate the…
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…
Primordial or big bang nucleosynthesis (BBN) is one of the three historical strong evidences for the big bang model. The recent results by the Planck satellite mission have slightly changed the estimate of the baryonic density compared to…
Primordial nucleosynthesis is inevitable during the early evolution of an expanding universe filled with radiation and matter (baryons). However, the precise abundance yields depend sensitively on the baryon density, the radiation content…
The primordial abundance of $^4$He plays a central role in big-bang nucleosynthesis (BBN) and in the cosmic microwave background (CMB). The LBT $Y_{\rm p}$ Project's new measurement of the primordial $^4$He mass fraction $Y_{\rm p} =0.2458…
The light relic density affects the thermal and expansion history of the early Universe leaving a number of observable imprints. We focus on the primordial abundances of light elements produced during the process of Big Bang nucleosynthesis…
We report the results on Big Bang Nucleosynthesis (BBN) based on an updated code, with accuracy of the order of 0.1% on He4 abundance, compared with the predictions of other recent similar analysis. We discuss the compatibility of the…
The primordial abundances of deuterium, helium-3, helium-4, and lithium-7 probe the baryon density of the Universe only a few minutes after the Big Bang. Of these relics from the early Universe, deuterium is the baryometer of choice. After…
The mixing between sterile and active neutrinos is taken into account in the calculation of Big Bang Nucleosynthesis. The abundances of primordial elements, like D, 3He, 4He and 7Li, are calculated by including sterile neutrinos, and by…
Big Bang nucleosynthesis in the presence of decaying relic neutral particles is examined in detail. All non-thermal processes important for the determination of light-element abundance yields of 2H, 3H, 3He, 4He, 6Li, and 7Li are coupled to…
We study primordial nucleosynthesis abundance yields for assumed ranges of cosmological lepton numbers, sterile neutrino mass-squared differences and active-sterile vacuum mixing angles. We fix the baryon-to-photon ratio at the value…