相关论文: Primordial heavy element production

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…

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…

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…

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…

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…

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…

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…

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…

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…

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…

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.…

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…

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…

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…

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…

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…

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…

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…

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…

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…