相关论文: Big Bang Nucleosynthesis
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…
There exist a range of exciting scientific opportunities for Big Bang Nucleosynthesis (BBN) in the coming decade. BBN, a key particle astrophysics "tool" for decades, is poised to take on new capabilities to probe beyond standard model…
We study effects of long-lived massive particles, which decay during the big-bang nucleosynthesis (BBN) epoch, on the primordial abundances of light elements. Compared to the previous studies, (i) the reaction rates of the standard BBN…
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 report the results of a new accurate evaluation of light nuclei yields in primordial nucleosynthesis. All radiative effects, finite nucleon mass, thermal and plasma corrections are included in the proton to neutron conversion rates. The…
The predictions of Standard Big Bang Nucleosynthesis are summarized and compared with observations of abundances of helium in HII regions, deuterium in quasar absorbers, deuterium and helium-3 in the Galaxy, and lithium in metal-poor stars.…
The role of neutrinos in big bang nucleosynthesis is discussed. The bounds on the number of neutrino families, neutrino degeneracy, parameters of neutrino oscillations are presented. A model of chemically inhomogeneous, while energetically…
Big Bang Nucleosynthesis (BBN) is the synthesis of the light nuclei, Deuterium, He3, He4 and Li7, during the first few minutes of the universe. This review concentrates on recent improvements in the measurement of the primordial (after BBN,…
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…
Big Bang Nucleosynthesis represents perhaps the first, and still perhaps the most powerful particle-astrophysics connection. As such, it should provide an example for other work in this area. I discuss the current status of standard model…
Big-bang nucleosynthesis (BBN) describes the production of the lightest nuclides via a dynamic interplay among the four fundamental forces during the first seconds of cosmic time. We briefly overview the essentials of this physics, and…
We review the Cosmology and Physics underlying Primordial Nucleosynthesis and survey current observational data in order to compare the predictions of Big Bang Nucleosynthesis with the inferred primordial abundances. From this comparison we…
Following a brief introduction to early Universe cosmology, the current of status of big bang nucleosynthesis is reviewed and the concordance between theory and observation is examined in detail. The abundances of He4 and Li7 determine the…
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…
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…
Big Bang Nucleosynthesis (BBN), as one of the earliest processes in the universe accessible to direct observation, offers a powerful and independent probe of the cosmic expansion history. With recent advances in both theory and observation,…
We consider Big Bang Nucleosynthesis(BBN) with long lived charged massive particles. Before decaying, the long lived massive particles recombines with a light element to form a bound state like a hydrogen atom. We discuss the possible…
We calculate primordial abundances of light elements produced during big bang nucleosynthesis when the fine structure constant and/or the cosmic expansion rate take non-standard values. We compare them with the recent values of observed D,…
The effects of radiatively decaying, long-lived particles on big-bang nucleosynthesis (BBN) are discussed. If high-energy photons are emitted after BBN, they may change the abundances of the light elements through photodissociation…
Standard big bang nucleosynthesis (SBBN) has been remarkably successful, and it may well be the correct and sufficient account of what happened. However, interest in variations from the standard picture come from two sources: First, big…