Related papers: The Baryon Budget from BBN and the CBR
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.…
A critical review is given of the current status of cosmological nucleosynthesis. In the framework of the standard model with 3 types of relativistic neutrinos, the baryon-to-photon ratio, \eta, corresponding to the inferred primordial…
We derive constraints on the injection of free-streaming dark radiation after big bang nucleosynthesis (BBN) by considering the decay of a massive hidden sector particle into dark radiation. Such a scenario has the potential to alleviate…
We assess the status of big-bang nucleosynthesis (BBN) in light of the final Planck data release and other recent developments, and in anticipation of future measurements. Planck data fix the cosmic baryon density to 0.9% precision, and…
Nucleosynthesis in the standard hot big bang cosmology offers a successful account of the production of the light nuclides during the early evolution of the Universe. Consistency among the predicted and observed abundances of D, $^3$He,…
In this paper we consider the effects on big bang nucleosynthesis (BBN) of the hadronic decay of a long-lived massive particle. If high-energy hadrons are emitted near the BBN epoch ($t \sim 10^{-2}$ -- $10^2 \sec$), they extraordinarily…
We present a model-independent reconstruction of the early expansion and thermal histories of the universe, obtained from light element abundance measurements. The expansion history is tightly constrained around the onset of the Big Bang…
The physics of the standard hot big bang cosmology ensures that the early Universe was a primordial nuclear reactor, synthesizing the light nuclides (D, 3He, 4He, and 7Li) in the first 20 minutes of its evolution. After an overview of…
We present a model for big bang nucleosynthesis which combines baryon inhomogeneities with the effects of the decays of massive particles (masses higher than a few GeV). Those particles, with half-lives longer than the standard…
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…
The successful prediction of light element abundances from Big Bang Nucleosynthesis has been a pillar of the standard model of Cosmology. Because many of the relevant reaction rates are sensitive to the values of fundamental constants, such…
Primordial nucleosynthesis remains as one of the pillars of modern cosmology. It is the testing ground upon which many cosmological models must ultimately rest. It is our only probe of the universe during the important radiation-dominated…
A critical review is given of the current status of cosmological nucleosynthesis. In the framework of the Standard Model with 3 types of relativistic neutrinos, the baryon-to-photon ratio, $\eta$, corresponding to the inferred primordial…
Big Bang Nucleosynthesis (BBN) is very sensitive to the cosmological expansion rate. If the gravitational constant $G$ took a different value during the nucleosynthesis epoch than today, the primordial abundances of light elements would be…
We consider the effect on Big Bang Nucleosynthesis (BBN) of new measurements of the $d(p,\gamma){}^3$He cross section by the LUNA Collaboration. These have an important effect on the primordial abundance of D/H which is also sensitive to…
Data from future high-precision Cosmic Microwave Background (CMB) measurements will be sensitive to the primordial Helium abundance $Y_p$. At the same time, this parameter can be predicted from Big Bang Nucleosynthesis (BBN) as a function…
The recently observed Deuterium abundance in a low- metallicity high-redshift hydrogen cloud, which is about ten times larger than that observed in the near interstellar medium, is that expected from the Standard Big Bang Nucleosynthesis…
We place constraints on the number of relativistic degrees of freedom and on the baryon asymmetry at the epoch of Big Bang Nucleosynthesis (BBN) and at recombination, using cosmic background radiation (CBR) data from the Wilkinson Microwave…
We explore constraints on extensions to the standard models of cosmology and particle physics which modify the early-Universe expansion rate S = H'/H (parametrized by the effective number of neutrinos N_nu). The constraints on N_nu and the…
Big-bang nucleosynthesis (BBN) theory, together with the precise WMAP cosmic baryon density, makes tight predictions for the abundances of the lightest elements. Deuterium and 4He measurements agree well with expectations, but 7Li…