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One of the still viable candidates for the dark matter is the so-called mirror matter. Its cosmological and astrophysical implications were widely studied in many aspects, pointing out the importance to go further with research and refine…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-14 Paolo Ciarcelluti

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

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…

High Energy Physics - Phenomenology · Physics 2011-04-14 Maxim Pospelov , Josef Pradler

To constrain the universe before recombination (380000 years after the Big Bang), we mostly rely on the measurements of the primordial abundances that indicate the first insight into the thermal history of the universe. The first production…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-30 Tahani Makki , Mounib El Eid , Grant Mathews

Primordial or Big Bang nucleosynthesis (BBN) is one of the three strong evidences for the Big- Bang model together with the expansion of the Universe and the Cosmic Microwave Background radiation. In this study, we improve the standard BBN…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Alain Coc , Stephane Goriely , Yi Xu , Matthias Saimpert , Elisabeth Vangioni

We consider the effects of the injections of energetic photon and electron (or positron) on the big-bang nucleosynthesis. We study the photodissociation of light elements in the early Universe paying particular attention to the case that…

High Energy Physics - Phenomenology · Physics 2021-01-06 Masahiro Kawasaki , Kazunori Kohri , Takeo Moroi , Kai Murai , Hitoshi Murayama

We study the big-bang nucleosynthesis (BBN) scenario with late-decaying exotic particles with lifetime longer than $\sim 1$ sec. With a late-decaying particle in the early universe, predictions of the standard BBN scenario can be…

Astrophysics · Physics 2010-04-05 Masahiro Kawasaki , Kazunori Kohri , Takeo Moroi

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…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Brian D. Fields , Paolo Molaro , Subir Sarkar

The ability to now make measurements of Be and B as well as put constraints on \lisix\ abundances in metal-poor stars has led to a detailed reexamination of Big Bang Nucleosynthesis in the $A\groughly6$ regime. The nuclear reaction network…

Astrophysics · Physics 2009-09-15 David Thomas , David N. Schramm , Keith A. Olive , Brian D. Fields

Assuming the lightest neutralino forms dark matter, we study its residual annihilation after freeze-out at the early universe. If taking place after the big bang nucleosynthesis (BBN) the annihilation products, especially at the hadronic…

High Energy Physics - Phenomenology · Physics 2008-04-17 Xiao-Jun Bi

Two dimensional concordance plots involving the baryon-to-photon ratio, $\eta$, and an effective number of light neutrinos, $N_{\nu}$, are used to discuss the overall consistency of standard big-bang nucleosynthesis in light of recent…

Astrophysics · Physics 2008-11-26 Christian Y. Cardall , George M. Fuller

Big bang nucleosynthesis (BBN) and the cosmic baryon density from cosmic microwave background anisotropies together predict a primordial Li7 abundance a factor of 2--3 higher than that observed in galactic halo dwarf stars. A recent…

Astrophysics · Physics 2008-12-18 Brian D. Fields , Keith A. Olive , Elisabeth Vangioni-Flam

The dual origin of population II Li7, in both big bang nucleosynthesis and galactic cosmic-ray nucleosynthesis is discussed. It is argued that with additional Li6 data, stringent limits on the degree of Li7 depletion can be obtained. Li7…

Astrophysics · Physics 2007-05-23 Keith A. Olive , Brian D. Fields

Many models of new physics including variants of supersymmetry predict metastable long-lived particles that can decay during or after primordial nucleosynthesis, releasing significant amounts of non-thermal energy. The hadronic energy…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-25 Maxim Pospelov , Josef Pradler

Comparing the latest observed abundances of 4He and D, we make a ?2 analysis to see whether it is possible to reconcile primordial nucleosynthesis using up-to-date nuclear data of NACRE II and the mean-life of neutrons. If we adopt the…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-05 R. Ichimasa , R. Nakamura , M. Hashimoto , K. Arai

The primordial lithium abundance inferred from observations of metal-poor stars is ~3 times smaller than the theoretical value in standard big bang nucleosynthesis (BBN) model. We assume a simple model including a sterile neutrino nu_H with…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-29 Hiroyuki Ishida , Motohiko Kusakabe , Hiroshi Okada

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…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-19 Brian D. Fields

Primordial nucleosynthesis is one of the three historical evidences for the big bang model, together with the expansion of the universe and the cosmic microwave background. Now that the number of neutrino families and the baryonic densities…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-07 Cyril Pitrou , Alain Coc , Jean-Philippe Uzan , Elisabeth Vangioni

In this paper we investigate the primordial nucleosynthesis in $\mathscr{L}=\varepsilon^{2-2\beta}R^\beta+{16\pi}m_P^{-2}\mathscr{L}_m$ gravity, where $\varepsilon$ is a constant balancing the dimension of the field equation, and…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-11 David Wenjie Tian

In the standard hot big bang nucleosynthesis (BBN) model the primordial abundances of H, H2, He3, He4, and Li7, fix the baryon density of the universe, $\Omega_b$, via the baryon-to-photon ratio, $\eta$, for a given Hubble parameter. Recent…

Astrophysics · Physics 2009-10-31 S. G. Ryan , T. C. Beers , K. A. Olive , B. D. Fields , J. E. Norris
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