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Primordial nucleosynthesis provides a probe of the universal abundance of baryons when the universe was only a few minutes old. Recent observations of anisotropy in the cosmic microwave background (CMB) probe the baryon abundance when the…

Astrophysics · Physics 2007-05-23 G. Steigman , J. P. Kneller , A. Zentner

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…

Astrophysics · Physics 2009-10-31 J. A. de Freitas Pacheco , S. Stoica , F. Thevenin , J. E. Horvath

The light element abundances probe the baryon density of the universe within a few minutes of the Big Bang. Of these relics from the earliest universe, deuterium is the baryometer of choice. By comparing its primordial abundance inferred…

Astrophysics · Physics 2015-06-24 Gary Steigman

We show that primordial nucleosynthesis in baryon inhomogeneous big-bang models can lead to significant heavy-element production while still satisfying all the light-element abundance constraints including the low lithium abundance observed…

Astrophysics · Physics 2009-10-22 K. Jedamzik , G. M. Fuller , G. J. Mathews , T. Kajino

The R\'{e}nyi entropy, a one-parameter generalization of Boltzmann-Gibbs entropy, offers a promising framework for probing quantum gravitational effects in cosmology. By modifying the entropy-area relation of the apparent horizon, R\'{e}nyi…

General Physics · Physics 2025-07-22 Ahmad Sheykhi , Ava Shahbazi Sooraki

We study the effect from a general ultralocal supermetric on primordial nucleosynthesis for Friedmann-Robertson-Walker Cosmology. The parameter $\lambda$ of the supermetric changes the effective number of degrees of freedom, $g_*$, which…

Astrophysics · Physics 2010-11-01 A. Llorente , J. Perez-Mercader

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…

Astrophysics · Physics 2008-11-26 Lawrence M. Krauss

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…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-21 Masahiro Kawasaki , Motohiko Kusakabe

We investigate the effect on the Big Bang Nucleosynthesis (BBN) from the presence of a stochastic primordial magnetic field (PMF) whose strength is spatially inhomogeneous. We assume a uniform total energy density and a gaussian…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-27 Yudong Luo , Toshitaka Kajino , Motohiko Kusakabe , Grant J. Mathews

The theory of Big Bang nucleosynthesis, coupled with an estimate of the primordial deuterium abundance (D/H)_pr, offers insights into the baryon density of the Universe. Independently, the baryon density can be constrained during a…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-24 P. A. Kislitsyn , S. A. Balashev , M. T. Murphy , C. Ledoux , P. Noterdaeme , A. V. Ivanchik

The primordial 7Li abundance predicted by standard Big Bang Nucleosynthesis (BBN) exceeds that inferred from old, metal-poor stars by a factor of about 3-4. In standard BBN, most primordial 7Li is produced as 7Be in the early Universe and…

Nuclear Theory · Physics 2026-01-21 Simone Taioli , Francesca Triggiani , Stefano Simonucci

We study the impact of an early dark energy component (EDE) present during big bang nucleosynthesis (BBN) on the elemental abundances of deuterium D/H, and helium $Y_p$, as well as the effective relativistic degrees of freedom $N_{\rm…

High Energy Physics - Phenomenology · Physics 2024-11-18 David McKeen , Afif Omar

Primordial or big bang nucleosynthesis (BBN) is now a parameter free theory whose predictions are in good overall agreement with observations. However, the 7Li calculated abundance is significantly higher than the one deduced from…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-20 Alain Coc

The most recent observations by the WMAP satellite provided us with data of unprecedented accuracy regarding the parameters describing the Standard Cosmological Model. The current matter-energy density of the Universe is close to its…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. B. Lahanas

Recent updates to the observational determinations of the primordial abundances of helium and deuterium are compared to the predictions of BBN to infer the universal ratio of baryons to photons (or, the present Universe baryon mass density…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-23 Gary Steigman , Kenneth M. Nollett

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…

Astrophysics · Physics 2009-06-23 Vimal Simha , Gary Steigman

The primordial abundances of Deuterium, he4, and li7 are crucial to determination of the baryon density of the Universe in the framework of standard Big Bang nucleosynthesis (BBN). li6 which is only produced in tiny quantities and it is…

We present calculations showing that upcoming Cosmic Microwave Background (CMB) experiments will have the power to improve on current constraints on neutrino masses and provide new limits on neutrino degeneracy parameters. The latter could…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 M. Shimon , N. J. Miller , C. T. Kishimoto , C. J. Smith , G. M. Fuller , B. G. Keating

We consider the big bang nucleosynthesis (BBN) in the Brane world scenario, where all matter fields are confined on our 3-brane and the radion of the Brane evolves cosmologically. In the Einstein frame fundamental fermion masses vary and…

Astrophysics · Physics 2009-11-13 Baojiu Li , Ming-Chung Chu

Big Bang nucleosynthesis (BBN) is the earliest sensitive probe of the values of many fundamental particle physics parameters. We have found the leading linear dependences of primordial abundances on all relevant parameters of the standard…

Astrophysics · Physics 2008-11-26 Thomas Dent , Steffen Stern
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