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Related papers: Primordial heavy element production

200 papers

We demonstrate that nucleosynthesis in rapid, high-entropy expansions of proton-rich matter from high temperature and density can result in a wider variety of abundance patterns than heretofore appreciated. In particular, such expansions…

Astrophysics · Physics 2009-11-10 G. C. Jordan , B. S. Meyer

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

The rapid neutron capture process (r process) is believed to be responsible for about half of the production of the elements heavier than iron and contributes to abundances of some lighter nuclides as well. A universal pattern of r-process…

High Energy Astrophysical Phenomena · Physics 2019-06-26 T. Kajino , W. Aoki , A. B. Balantekin , R. Diehl , M. A. Famiano , G. J. Mathews

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

Primordial Black Holes could be an important component of the dark matter in the Universe. If they exist, they would add a Poisson component to the matter power spectrum. The extra power would speed up the emergence of dark matter halos…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-16 F. Atrio-Barandela

We review recent work examining the influence of fission in rapid neutron capture ($r$-process) nucleosynthesis which can take place in astrophysical environments. We briefly discuss the impact of uncertain fission barriers and fission…

Nuclear Theory · Physics 2020-06-22 Nicole Vassh , Matthew R. Mumpower , Trevor M. Sprouse , Rebecca Surman , Ramona Vogt

New elemental abundances for the neutron-capture elements Sr, Nb, Mo, Ru, La, Sm, and Eu are presented for a large sample of 180 barium (Ba) giant stars, a class of chemically peculiar objects that exhibit in their spectra enhancements of…

Solar and Stellar Astrophysics · Physics 2021-08-19 M. P. Roriz , M. Lugaro , C. B. Pereira , C. Sneden , S. Junqueira , A. I. Karakas , N. A. Drake

Z-boson exchange interaction induces attractive force between left-handed neutrino and neutron. The Ginzburg-Landau mean field calculation and the Bogoliubov transformation suggest that this attractive force leads to neutrino-neutron pair…

High Energy Physics - Phenomenology · Physics 2022-09-13 M. Yoshimura

Big-bang nucleosynthesis is one of the cornerstones of the standard cosmology. For almost thirty years its predictions have been used to test the big-bang model to within a fraction of a second of the bang. The concordance that exists…

Astrophysics · Physics 2009-10-22 Craig J Copi , David N. Schramm , Michael S. Turner

We consider the possibility that some primordial fields decay purely into the dark sector creating asymmetric dark matter. This asymmetry is subsequently transmuted into leptons and baryons. Within this paradigm we compute the amount of…

High Energy Physics - Phenomenology · Physics 2013-10-07 Wan-Zhe Feng , Anupam Mazumdar , Pran Nath

Heavy right handed neutrinos could not only explain the observed neutrino masses via the seesaw mechanism, but also generate the baryon asymmetry of the universe via leptogenesis due to their CP-violating interactions in the early universe.…

High Energy Physics - Phenomenology · Physics 2016-11-28 Marco Drewes , Bjorn Garbrecht , Dario Gueter , Juraj Klaric

Generating axion dark matter through the kinetic misalignment mechanism implies the generation of large asymmetries for Standard Model fermions in the early universe. Even if these asymmetries are washed out at later times, they can trigger…

High Energy Physics - Phenomenology · Physics 2023-08-09 Raymond T. Co , Valerie Domcke , Keisuke Harigaya

In view of several conflicting results, we reanalyze the effects of magnetic fields on the primordial nucleosynthesis. In the case the magnetic field is homogeneous over a horizon volume, we show that the main effects of the magnetic field…

Astrophysics · Physics 2008-11-26 D. Grasso , H. R. Rubinstein

Recent studies suggest that metal-poor stars enhanced in carbon but containing low levels of neutron-capture elements may have been among the first to incorporate the nucleosynthesis products of the first generation of stars. We have…

Solar and Stellar Astrophysics · Physics 2015-06-18 Ian U. Roederer , George W. Preston , Ian B. Thompson , Stephen A. Shectman , Chris Sneden

The light relic density affects the thermal and expansion history of the early Universe leaving a number of observable imprints. We focus on the primordial abundances of light elements produced during the process of Big Bang nucleosynthesis…

Cosmology and Nongalactic Astrophysics · Physics 2020-02-19 Alex Laguë , Joel Meyers

We propose a new neutron-capture site in early metal-poor and metal-free stars of $\sim 20$--$30 \,\mathrm{M}_\odot$ that results from proton ingestion in the He shell during late stages of the stars' lives. Most of the neutron capture…

Solar and Stellar Astrophysics · Physics 2018-10-12 Projjwal Banerjee , Yong-Zhong Qian , Alexander Heger

It was recently suggested that dark matter consists of ~GeV particles that carry baryon number and mix with the neutron. We demonstrate that this could allow for resonant dark matter-neutron oscillations in the early universe, at finite…

High Energy Physics - Phenomenology · Physics 2019-07-10 Torsten Bringmann , James M. Cline , Jonathan M. Cornell

We study the effects of dark-matter annihilation during the epoch of big-bang nucleosynthesis on the primordial abundances of light elements. We improve the calculation of the light-element abundances by taking into account the effects of…

High Energy Physics - Phenomenology · Physics 2015-10-28 Masahiro Kawasaki , Kazunori Kohri , Takeo Moroi , Yoshitaro Takaesu

We study the dynamics of the early universe in massive conformal gravity. In particular, we show that the theory is consistent with the observed values of the primordial abundances of light elements if we consider the existence of…

General Physics · Physics 2023-02-15 F. F. Faria

In the standard hot big bang model, the expansion of the early universe is given by the Friedmann equation with an energy density dominated by relativistic particles. Since in a variety of models this equation is altered, we introduce…

Astrophysics · Physics 2016-08-16 Eduard Massó , Francesc Rota