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Big bang nucleosynthesis (BBN) and the cosmic microwave background (CMB) are two major pillars of cosmology. Standard BBN accurately predicts the primordial light element abundances ($^4$He, D, $^3$He and $^7$Li), depending on one…

Astrophysics · Physics 2009-11-10 Greg Huey , Richard H. Cyburt , Benjamin D. Wandelt

Big Bang Nucleosynthesis can provide, via constraints on the expansion rate at that time, limits on possible variations in Newton's Constant, $G$. The original analyses were performed before an independent measurement of the…

Astrophysics · Physics 2009-11-10 Craig J. Copi , Adam N. Davis , Lawrence M. Krauss

The current uncertainty in Newton's constant, G_N, is of the order of 0.15%. For values of the baryon to photon ratio consistent with both cosmic microwave background observations and the primordial deuterium abundance, this uncertainty in…

Astrophysics · Physics 2008-11-26 Robert J. Scherrer

Cosmic microwave background (CMB) determinations of the baryon-to-photon ratio $\eta \propto \Omega_{\rm baryon} h^2$ will remove the last free parameter from (standard) big bang nucleosynthesis (BBN) calculations. This will make BBN a much…

Astrophysics · Physics 2008-11-26 Richard H. Cyburt , Brian D. Fields , Keith A. Olive

We update the Big Bang Nucleosynthesis calculations on the basis of the recent NACRE compilation. The average values of the calculated abundances of light nuclei do not differ significantly from that obtained using the previous Fowler's…

Astrophysics · Physics 2016-08-30 Elisabeth Vangioni-Flam , Alain Coc , Michel Casse

We reinvestigate the constraints from primordial nucleosynthesis on a possible time-dependent quark mass. The limits on such quark-mass variations are particularly sensitive to the adopted observational abundance constraints. Hence, in the…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-06 Myung-Ki Cheoun , Toshitaka Kajino , Motohiko Kusakabe , Grant J. Mathews

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

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

We reexamine big bang nucleosynthesis with large-scale baryon density inhomogeneities when the length scale of the density fluctuations exceeds the neutron diffusion length ($\sim 10^7-10^8$ cm at BBN), and the amplitude of the fluctuations…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-12 John D. Barrow , Robert J. Scherrer

We derive constraints from standard (with $N_\nu = 3$) BBN arising solely from two cosmologically produced nuclides, \he4 and \li7, from which the extrapolation to primordial abundances is straightforward. The abundances of D and \he3 are…

High Energy Physics - Phenomenology · Physics 2009-09-15 Brian D. Fields , Keith A. Olive

Big Bang Nucleosynthesis (BBN) relates key cosmological parameters to the primordial abundance of light elements. In this paper, we point out that the recent observations of Cosmic Microwave Background anisotropies by the Planck satellite…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-06 Eleonora Di Valentino , Carlo Gustavino , Julien Lesgourgues , Gianpiero Mangano , Alessandro Melchiorri , Gennaro Miele , Ofelia Pisanti

The simplest, `standard' model of Big Bang Nucleosynthesis (SBBN) assumes three light neutrinos (N_nu = 3) and no significant electron neutrino asymmetry, leaving only one adjustable parameter: the baryon to photon ratio eta. The primordial…

Astrophysics · Physics 2009-11-10 James P. Kneller , Gary Steigman

We have calculated the small effect of finite nucleon mass on the weak-interaction rates that interconvert protons and neutrons in the early Universe. We have modified the standard code for primordial nucleosynthesis to include these…

Astrophysics · Physics 2009-12-30 Robert E. Lopez , Michael S. Turner , Geza Gyuk

The early, hot, dense, expanding Universe was a primordial reactor in which the light nuclides D, 3He, 4He and 7Li were synthesized in astrophysically interesting abundances. The challenge to the standard hot big bang model (Big Bang…

Astrophysics · Physics 2007-05-23 Gary Steigman

We perform the first quantitative study of the sensitivity of Big Bang Nucleosynthesis to variations in isospin breaking with precise input from lattice QCD calculations. The predicted light nuclear abundances are most sensitive to the…

Nuclear Theory · Physics 2017-06-16 Matthew Heffernan , Projjwal Banerjee , Andre Walker-Loud

Big Bang nucleosynthesis in the presence of decaying relic neutral particles is examined in detail. All non-thermal processes important for the determination of light-element abundance yields of 2H, 3H, 3He, 4He, 6Li, and 7Li are coupled to…

High Energy Physics - Phenomenology · Physics 2009-11-11 Karsten Jedamzik

Nuclear reaction rates are among the most important input for understanding the primordial nucleosynthesis and therefore for a quantitative description of the early Universe. An up-to-date compilation of direct cross sections of 2H(d,p)3H,…

The primordial abundance of $^4$He plays a central role in big-bang nucleosynthesis (BBN) and in the cosmic microwave background (CMB). The LBT $Y_{\rm p}$ Project's new measurement of the primordial $^4$He mass fraction $Y_{\rm p} =0.2458…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-02 Tsung-Han Yeh , Keith A. Olive , Brian D. Fields , Erik Aver , Richard W. Pogge , Noah S. J. Rogers , Evan D. Skillman , Miqaela K. Weller

We extend the model-independent likelihood analysis of big bang nucleosynthesis (BBN) based on He4 and Li7 to allow for numbers of degrees of freedom which differ from the standard model value characterized by $N_\nu = 3$. We use the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Keith A. Olive , David Thomas

Big bang nucleosynthesis has long provided the primary determination of the cosmic baryon density $\omb h^2$, or equivalently the baryon-to-photon ratio, \eta. Recently, data on CMB anisotropies have become increasingly sensitive to \eta.…

Astrophysics · Physics 2008-11-26 Richard H. Cyburt , Brian D. Fields , Keith A. Olive
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