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In this work, we investigate the viability of some cosmological models derived from generalized horizon entropies, using Big Bang Nucleosynthesis (BBN) constraints. By analyzing the deviations in the expansion rate, we derive bounds on the…

General Relativity and Quantum Cosmology · Physics 2026-04-22 Kajal Phukan , Rajdeep Mazumdar , Kalyan Malakar , Kalyan Bhuyan

The observed abundances of Li7 and He4 are significantly inconsistent with the predictions from Big Bang Nucleosynthesis (BBN) when using the LCDM cosmological model together with the value for Omega_Bh^2 = 0.0224 +/- 0.0009 from WMAP CMB…

General Physics · Physics 2009-11-19 Reginald T. Cahill

Primordial nucleosynthesis, or big bang nucleosynthesis (BBN), is one of the three evidences for the big bang model, together with the expansion of the universe and the cosmic microwave background. There is a good global agreement over a…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-20 Alain Coc , Elisabeth Vangioni

During its hot, dense, early evolution the Universe was a primordial nuclear reactor, synthesizing the light nuclides D, 3He, 4He and 7Li in the first thousand seconds. The presently observed abundances of these relic nuclides provide a…

Astrophysics · Physics 2007-05-23 G. Steigman

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…

Astrophysics · Physics 2007-05-23 Gary Steigman

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…

Astrophysics · Physics 2007-05-23 Brian Fields , Subir Sarkar

We note that the standard LCDM cosmological model continues to face fundamental problems. First, the model continues to depend wholly on two pieces of undiscovered physics, namely dark energy and cold dark matter. Then, the implied dark…

Astrophysics · Physics 2019-10-23 T. Shanks

Detections of deuterium in high redshift Lyman limit absorption systems along the line of sight to QSOs promise to reveal the primordial deuterium abundance. At present, the deuterium abundances (D/H) derived from the very few systems…

Astrophysics · Physics 2009-10-28 K. Jedamzik , G. M. Fuller

Ultralight scalar dark matter can interact with all massive Standard Model particles through a universal coupling. Such a coupling modifies the Standard Model particle masses and affects the dynamics of Big Bang Nucleosynthesis. We model…

High Energy Physics - Phenomenology · Physics 2020-12-16 Sergey Sibiryakov , Philip Sørensen , Tien-Tien Yu

The synthesis of helium in the early Universe depends on many input parameters, including the value of the gravitational coupling during the period when the nucleosynthesis takes place. We compute the primordial abundance of helium as…

General Relativity and Quantum Cosmology · Physics 2015-06-25 F. G. Alvarenga , J. C. Fabris , S. V. B. Goncalves , J. A. O. Marinho

I summarize the stellar side of the cosmological lithium problem(s). Evidence from independent studies is accumulating and indicates that stars may very well be fully responsible for lowering their surface lithium from the predicted…

Solar and Stellar Astrophysics · Physics 2024-06-17 A. J. Korn

The cosmological lithium problem, i.e. the discrepancy between the lithium abundance predicted by the Big Bang Nucleosynthesis and the one observed for the stars of the "Spite plateau", is one of the long standing problems of modern…

Solar and Stellar Astrophysics · Physics 2020-04-17 S. Cassisi , M. Salaris , S. Degl'Innocenti , P. G. Prada Moroni , E. Tognelli

Two groups have independently reported the possible detection of extragalactic deuterium in the absorption spectrum of the same high redshift, low metalicity QSO. Although the high value for the inferred deuterium abundance poses no…

Astrophysics · Physics 2016-06-08 Gary Steigman

Constraints on big bang nucleosynthesis (BBN) and on cosmological parameters from conflicting deuterium observations in different high red-shift QSO systems are discussed. The high deuterium observations by Carswell et al., Songaila et al.,…

Astrophysics · Physics 2008-11-26 N. Hata , G. Steigman , S. Bludman , P. Langacker

Recent measurements of the D(p,$\gamma)^3$He, nuclear reaction cross-section and of the neutron lifetime, along with the reevaluation of the cosmological baryon abundance from cosmic microwave background (CMB) analysis, call for an update…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-17 Cyril Pitrou , Alain Coc , Jean-Philippe Uzan , Elisabeth Vangioni

The main foundations of the standard $\Lambda $CDM model of cosmology are that: 1) The redshifts of the galaxies are due to the expansion of the Universe plus peculiar motions; 2) The cosmic microwave background radiation and its…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-08 Martin Lopez-Corredoira

The cosmological abundance of nucleons determined from considerations of Big Bang nucleosynthesis allegedly provides compelling evidence for non-nucleonic dark matter. Recent developments in measurements of primordial light element…

Astrophysics · Physics 2007-05-23 Subir Sarkar

Primordial nucleosynthesis is a success story of the standard big bang (SBB) cosmology. We explore nucleosynthesis in possible models very different from SBB in which the cosmological scale factor increases linearly with time right through…

Nuclear Theory · Physics 2007-05-23 Daksh Lohiya , Annu Batra , Shobhit Mahajan , Amitabha Mukherjee

We present new upper and lower bounds to the primordial abundances of deuterium and helium-3 based on observational data from the solar system and the interstellar medium. Independent of any model for the primordial production of the…

Astrophysics · Physics 2009-10-22 N. Hata , R. J. Scherrer , G. Steigman , D. Thomas , T. P. Walker

The lack of experimental evidence at the LHC for physics beyond the Standard model (BSM) of elementary particles together with necessity of its existence to provide solutions of internal problems of the Standard model (SM) as well as of…

High Energy Physics - Phenomenology · Physics 2019-11-11 Maxim Yu. Khlopov