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The current of status of big bang nucleosynthesis is reviewed and the concordance between theory and observation is examined in detail. It is argued that when using the observational data on he4 and li7, the two isotopes whose abundances…

Astrophysics · Physics 2008-02-03 Keith A. Olive

We propose new estimates for the frontier of a set of points. They are defined as kernel estimates covering all the points and whose associated support is of smallest surface. The estimates are written as linear combinatio- ns of kernel…

Methodology · Statistics 2011-03-31 Guillaume Bouchard , Stéphane Girard , Anatoli Iouditski , Alexander Nazin

We prove an elementary yet useful inequality bounding the maximal value of certain linear programs. This leads directly to a bound on the martingale difference for arbitrarily dependent random variables, providing a generalization of some…

Functional Analysis · Mathematics 2007-05-23 Leonid Kontorovich

The success of primordial nucleosynthesis has been limited by the long-standing Lithium problem. We use a self-consistent perturbative analysis of the effects of relevant theoretical parameters on primordial nucleosynthesis, including…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-08 M. Deal , C. J. A. P. Martins

An infinite set is orbit-finite if, up to permutations of the underlying structure of atoms, it has only finitely many elements. We study a generalisation of linear programming where constraints are expressed by an orbit-finite system of…

Logic in Computer Science · Computer Science 2024-11-14 Arka Ghosh , Piotr Hofman , Sławomir Lasota

We have modified the standard code for primordial nucleosynthesis to include the effect of finite nucleon mass on the weak-interaction rates as calculated by Seckel \cite{seckel}. We find a small, systematic increase in the $^4$He yield,…

Astrophysics · Physics 2007-05-23 Geza Gyuk , Michael S. Turner

Recently conformal Weyl gravity has been considered as a candidate alternative gravity theory. This fourth-order theory is attractive because it is the only metric theory of gravity which is invariant under local conformal transformations…

Astrophysics · Physics 2009-09-25 Lloyd Knox , Arthur Kosowsky

A massive long-lived tau neutrino in the MeV regime modifies the primordial light-element abundances predicted by big-bang nucleosynthesis (BBN) calculations. This effect has been used to derive limits on the tau neutrino mass. Because…

Astrophysics · Physics 2011-05-23 J. B. Rehm , G. G. Raffelt , A. Weiss

In this short paper, we give an upper bound for the number of different basic feasible solutions generated by the simplex method for linear programming problems having optimal solutions. The bound is polynomial of the number of constraints,…

Optimization and Control · Mathematics 2015-03-17 Tomonari Kitahara , Shinji Mizuno

A matching in a graph is induced if no two of its edges are joined by an edge, and finding a large induced matching is a very hard problem. Lin et al. (Approximating weighted induced matchings, Discrete Applied Mathematics 243 (2018)…

Combinatorics · Mathematics 2018-12-17 Julien Baste , Maximilian Fürst , Dieter Rautenbach

The problem of establishing out-of-sample bounds for the values of an unkonwn ground-truth function is considered. Kernels and their associated Hilbert spaces are the main formalism employed herein along with an observational model where…

Machine Learning · Computer Science 2022-09-13 Paul Scharnhorst , Emilio T. Maddalena , Yuning Jiang , Colin N. Jones

We study the primordial nucleosynthesis and cosmic age in the presence of a net lepton asymmetry as well as baryon asymmetry. We explore a previously unnoted region of the parameter space in which very large baryon densities $0.1 \le…

Astrophysics · Physics 2007-05-23 T. Kajino , M. Orito , G. J. Mathews , R. N. Boyd

We investigate the effect on the Big Bang Nucleosynthesis (BBN) from the presence of a stochastic primordial magnetic field (PMF) whose strength is spatially inhomogeneous. We assume a uniform total energy density and a gaussian…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-27 Yudong Luo , Toshitaka Kajino , Motohiko Kusakabe , Grant J. Mathews

We study the effect from a general ultralocal supermetric on primordial nucleosynthesis for Friedmann-Robertson-Walker Cosmology. The parameter $\lambda$ of the supermetric changes the effective number of degrees of freedom, $g_*$, which…

Astrophysics · Physics 2010-11-01 A. Llorente , J. Perez-Mercader

Contrary to a recent claim, the inferred primordial abundances of the light elements are quite consistent with the expectations from standard big bang nucleosynthesis when attention is restricted to direct observations rather than results…

Astrophysics · Physics 2008-11-26 Peter J. Kernan , Subir Sarkar

Assuming the best numerical value for the cosmic baryonic density and the existence of three neutrino flavors, standard big bang nucleosynthesis is a parameter-free model. It is important to assess if the observed primordial abundances can…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-07 Christian Iliadis , Alain Coc

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

This article presents an original code for Big Bang Nucleosynthesis in a baryon inhomogeneous model of the universe. In this code neutron diffusion between high and low baryon density regions is calculated simultaneously with the nuclear…

Astrophysics · Physics 2009-11-11 Juan F. Lara

Random Fourier Features (RFF) demonstrate wellappreciated performance in kernel approximation for largescale situations but restrict kernels to be stationary and positive definite. And for non-stationary kernels, the corresponding RFF could…

Machine Learning · Statistics 2021-04-15 Qin Luo , Kun Fang , Jie Yang , Xiaolin Huang

We investigate the observational constraints on the inhomogeneous big-bang nucleosynthesis that Matsuura et al. suggested the possibility of the heavy element production beyond ${}^7$Li in the early universe. From the observational…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-21 Riou Nakamura , Masa-aki Mashimoto , Shin-ichiro Fujimoto , Katsuhiko Sato