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Related papers: Big Bang nucleosynthesis with a non-Maxwellian dis…

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A variety of phenomena in nuclear and high energy physics seemingly do not satisfy the basic hypothesis for possible stationary states to be of the type covered by Boltzmann-Gibbs (BG) statistical mechanics. More specifically, the system…

Statistical Mechanics · Physics 2017-08-23 C. Tsallis , Ernesto P. Borges

We consider Big Bang nucleosynthesis and the cosmic microwave background when both the neutrino temperature and neutrino number are allowed to vary from their standard values. The neutrino temperature is assumed to differ from its standard…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-15 Richard Galvez , Robert J. Scherrer

We examine in detail how BBN theory is constrained, and what predictions it can make, when using only the most model-independent observational constraints. We avoid the uncertainties and model-dependencies that necessarily arise when solar…

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

Primordial nucleosynthesis is considered a success story of the standard big bang (SBB) cosmology. The cosmological and elementary particle physics parameters are believed to be severely constrained by the requirement of correct abundances…

Astrophysics · Physics 2007-05-23 Daksh Lohiya , Shobhit Mahajan , A. Mukherjee , Annu Batra

During the past dozen years there have been numerous articles on a relation between entropy and probability which is non-additive and has a parameter $q$ that depends on the nature of the thermodynamic system under consideration. For $q=1$…

Statistical Mechanics · Physics 2009-11-07 Michael Nauenberg

The thermal rates for converting neutrons to protons, and vice versa, are calculated, including corrections of order 1 MeV divided by a nucleon mass. The results imply that the primodial helium abundance predicted for big bang…

High Energy Physics - Phenomenology · Physics 2009-09-25 David Seckel

We investigate whether Big Bang nucleosynthesis (BBN) remains compatible with the Covarying Coupling Constants plus Tired Light (CCC+TL) cosmology. In this framework, only quantities with explicit length dimensionality covary through a…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-27 Rajendra P. Gupta , Nikolaos Samaras

We compute radiative corrections to nuclear reaction rates that determine the outcome of the Big-Bang Nucleosynthesis (BBN). Any nuclear reaction producing a photon with an energy above $2m_e$ must be supplemented by the corresponding…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-24 Cyril Pitrou , Maxim Pospelov

I review standard big bang nucleosynthesis and some versions of nonstandard BBN. The abundances of the primordial isotopes D, He-3, and Li-7 produced in standard BBN can be calculated as a function of the baryon density with an accuracy of…

Astrophysics · Physics 2021-04-28 Hannu Kurki-Suonio

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…

Cosmology and Nongalactic Astrophysics · Physics 2020-03-18 James Alvey , Nashwan Sabti , Miguel Escudero , Malcolm Fairbairn

Big Bang Nucleosynthesis (BBN), along with the cosmic background radiation and the Hubble expansion, is one of the pillars ofthe standard, hot, big bang cosmology since the primordial synthesis of the light nuclides (D, $^3$He, $^4$He,…

Astrophysics · Physics 2008-02-03 Gary Steigman

This is a reply report to astro-ph/0604264. We studied heavy element production in high baryon density region in early universe astro-ph/0507439. However it is claimed in astro-ph/0604264 that small scale but high baryon density region…

Astrophysics · Physics 2009-11-13 Shunji Matsuura , Shin-ichirou Fujimoto , Masa-aki Hashimoto , Katsuhiko Sato

Stellar nucleosynthesis is an important nuclear physics phenomenon that is responsible for presently observed chemical elements and isotope abundances. It is also one of the corner stone hypotheses that provides basis for our understanding…

Solar and Stellar Astrophysics · Physics 2012-03-09 Boris Pritychenko

The nonextensivity in a non-isothermal plasma system with the Coulombian long-range interactions is studied in the framework of Tsallis statistics. We present for first time a mathematical expression of the nonextensive parameter q based on…

Statistical Mechanics · Physics 2015-08-10 Jiulin Du

The statistical mechanics of a cloud of particles interacting via their gravitational potentials is an old problem which encounters some issues when the traditional Boltzmann-Gibbs statistics is applied. In this article, we consider the…

Statistical Mechanics · Physics 2018-04-10 Lenin Escamilla-Herrera , Christine Gruber , Viridiana Pineda , Hernando Quevedo

We update the Big Bang Nucleosynthesis (BBN) calculations on the basis of the recent NACRE compilation of reaction rates. We estimate the uncertainties related to the nuclear reaction rates on the abundances of D, 3He, 4He, 6Li, 7Li, 9Be,…

Astrophysics · Physics 2009-10-31 Elisabeth Vangioni-Flam , Alain Coc , Michel Casse

The light elements up to 7Li were produced by the Standard Big Bang nucleosynthesis (SBBN) in the early universe assuming standard conditions. All observed primordial abundances of these light elements match very well the predicted ones by…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-07 Tahani R. Makki , Mounib F. El Eid , Grant J. Mathews

Primordial or big bang nucleosynthesis (BBN) is one of the three historical strong evidences for the big bang model. Standard BBN is now a parameter free theory, since the baryonic density of the Universe has been deduced with an…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-30 Alain Coc , Patrick Petitjean , Jean-Philippe Uzan , Elisabeth Vangioni , Pierre Descouvemont , Christian Illiadis , Richard Longland

Quasi-power law ensembles are discussed from the perspective of nonextensive Tsallis distributions characterized by a nonextensive parameter $q$. A number of possible sources of such distributions are presented in more detail. It is further…

Statistical Mechanics · Physics 2023-07-19 Grzegorz Wilk , Zbigniew Włodarczyk

A formal correspondence between the q-distribution obtained from the Tsallis entropy and non-maxwellian distributions obtained from the Boltzmann-Gibbs entropy is afforded.

Quantum Physics · Physics 2009-11-13 N. G. de Almeida