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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

The theory of large deviations constitutes a mathematical cornerstone in the foundations of Boltzmann-Gibbs statistical mechanics, based on the additive entropy $S_{BG}=- k_B\sum_{i=1}^W p_i \ln p_i$. Its optimization under appropriate…

Statistical Mechanics · Physics 2011-10-31 Guiomar Ruiz , Constantino Tsallis

We update Standard Big Bang Nucleosynthesis (SBBN) calculations on the basis of recent nuclear physics compilations (NACRE in particular), experimental and theoretical works. By a Monte--Carlo technique, we calculate the uncertainties on…

Astrophysics · Physics 2009-11-07 Alain Coc , Elisabeth Vangioni-Flam , Michel Cass'e , Marc Rabiet

We study effects of relic long-lived strongly interacting massive particles (X particles) on big bang nucleosynthesis (BBN). The X particle is assumed to have existed during the BBN epoch, but decayed long before detected. The interaction…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Motohiko Kusakabe , Toshitaka Kajino , Takashi Yoshida , Grant J. Mathews

The Maxwell-Boltzmannian approach to nuclear reaction rate theory is extended to cover Tsallis statistics (Tsallis, 1988) and more general cases of distribution functions. An analytical study of respective thermonuclear functions is being…

Astrophysics · Physics 2009-06-23 H. J. Haubold , D. Kumar

Recently it is reported that there is the discrepancy between big bang nucleosynthesis theory and observations (BBN crisis). We show that BBN predictions agree with the primordial abundances of light elements, He4, D, He3 and Li7 inferred…

Astrophysics · Physics 2008-11-26 K. Kohri , M. Kawasaki , Katsuhiko Sato

The properties of the nonextensive parameter q and the Tsallis distribution for self-gravitating systems are studied. A mathematical expression of q is deduced based on the generalized Boltzmann equation, the q-H theorem and the generalized…

Statistical Mechanics · Physics 2015-08-10 Jiulin Du

Recent work [Wild et al., Nature 615, 425 (2023)] has provided an experimental break-through in the realization of a quantum-tunneling reaction involving a proton transfer. The reaction $D^-+H_2 \to H^-+HD$ has an extremely slow reaction…

Statistical Mechanics · Physics 2024-11-26 Christian Beck , Constantino Tsallis

We derive and study quasicanonical Gibbs distribution function which is characterized by the thermostat with finite number of particles (quasithermostat). We show that this naturally leads to Tsallis nonextensive statistics and…

Statistical Mechanics · Physics 2007-05-23 A. K. Aringazin , M. I. Mazhitov

In this paper we will show that, because of the long-range microscopic memory of the random force, acting in the solar core, mainly on the electrons and the protons than on the light and heavy ions (or, equally, because of anomalous…

Astrophysics · Physics 2011-04-15 G. Kaniadakis , A. Lavagno , P. Quarati

Following the basic prescriptions of the Tsallis' nonextensive relativistic thermodynamics, we investigate the relevance of nonextensive statistical effects on the relativistic nuclear and subnuclear equation of state. In this framework, we…

Nuclear Theory · Physics 2015-05-14 A. Lavagno , P. Quarati , A. M. Scarfone

We numerically study a one-dimensional system of $N$ classical localized planar rotators coupled through interactions which decay with distance as $1/r^\alpha$ ($\alpha \ge 0$). The approach is a first principle one (\textit{i.e.}, based on…

Statistical Mechanics · Physics 2013-11-05 Leonardo J. L. Cirto , Vladimir R. V. Assis , Constantino Tsallis

We consider the effect of inhomogeneous neutrino degeneracy on Big Bang nucleosynthesis for the case where the distribution of neutrino chemical potentials is given by a Gaussian. The chemical potential fluctuations are taken to be…

Astrophysics · Physics 2009-11-07 Spencer D. Stirling , Robert J. Scherrer

We investigate Big Bang nucleosynthesis (hereafter, BBN) in a cosmic environment characterized by a distribution of small-scale matter/antimatter domains. Production of antimatter domains in a baryo-asymmetric universe is predicted in some…

Astrophysics · Physics 2009-10-30 Jan B. Rehm , Karsten Jedamzik

We test different Big Bang Nucleosynthesis scenarios using the recent results on the Cosmic Microwave Background Anisotropies provided by the BOOMERanG and MAXIMA-1 experiments versus the observed abundances of 4He, D and 7Li. The…

Astrophysics · Physics 2009-10-31 S. Esposito , G. Mangano , A. Melchiorri , G. Miele , O. Pisanti

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

We consider the Big Bang Nucleosynthesis (BBN) bounds on light dark matter whose cross section off nucleons is sufficiently large to enable acceleration by scattering off of cosmic rays in the local galaxy. Such accelerated DM could then…

High Energy Physics - Phenomenology · Physics 2020-07-01 Gordan Krnjaic , Samuel D. McDermott

We examine big bang nucleosynthesis (BBN) in models with a time-varying gravitational constant $G$, when this time variation is rapid on the scale of the expansion rate $H$, i.e, $\dot G/G \gg H$. Such models can arise naturally in the…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-19 Anish Giri , Robert J. Scherrer

We investigate the non-radiative decay during nucleosynthesis of a massive tau neutrino with mass 0.1 - 1 MeV into an electron neutrino and a scalar or pseudoscalar particle, $\phi$. The full Boltzmann equation is used and shown to give…

High Energy Physics - Phenomenology · Physics 2009-10-30 S. Hannestad

There is a conception that Boltzmann-Gibbs statistics cannot yield the long tail distribution. This is the justification for the intensive research of nonextensive entropies (i.e. Tsallis entropy and others). Here the error that caused this…

Information Theory · Computer Science 2009-06-30 Oded Kafri