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Related papers: Nucleosynthesis at Finite Temperature and Density

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A variation of the fundamental constants is expected to affect the thermonuclear rates important for stellar nucleosynthesis. In particular, because of the very small resonant energies of Be8 and C12, the triple $\alpha$ process is…

Solar and Stellar Astrophysics · Physics 2014-11-20 Sylvia Ekstrom , Alain Coc , Pierre Descouvemont , Georges Meynet , Keith A. Olive , Jean-Philippe Uzan , Elisabeth Vangioni

Except for 1H, 2H, 3He, 4He, and 7Li, originating from the Big Bang, all heavier elements are made in stellar evolution and stellar explosions. Nuclear physics, and in many cases nuclear structure far from stability, enters in a crucial…

We examine the Pb and Th abundances in 27 metal-poor stars (-3.1 < [Fe/H] < -1.4) whose very heavy metal (Z > 56) enrichment was produced only by the rapid (r-) nucleosynthesis process. New abundances are derived from HST/STIS, Keck/HIRES,…

Solar and Stellar Astrophysics · Physics 2011-02-11 Ian U. Roederer , Karl-Ludwig Kratz , Anna Frebel , Norbert Christlieb , Bernd Pfeiffer , John J. Cowan , Christopher Sneden

The influence of the electron environment on the alpha decay is elucidated. Within the frame of a simple model based on the generalized Thomas-Fermi theory of the atom, it is shown that the increase of the electron density around the parent…

Nuclear Theory · Physics 2017-04-03 Fabio Belloni

We study the effect of neutrino degeneracy on primordial nucleosynthesis in a universe in which the cosmological scale factor evolves linearly with time. The degeneracy parameter of electron type neutrinos ($\xi_e$) determines the $n/p$…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-02 Parminder Singh , Daksh Lohiya

We investigate the possibility that neutrino capture on heavy nuclei competes with beta decay in the environment where the $r$-Process elements are synthesized. We find that such neutrino capture is not excluded by existing abundance…

Astrophysics · Physics 2016-08-30 Gail C. McLaughlin , George M. Fuller

We analyze the effect of variation of fundamental couplings and mass scales on primordial nucleosynthesis in a systematic way. The first step establishes the response of primordial element abundances to the variation of a large number of…

Astrophysics · Physics 2008-12-18 Thomas Dent , Steffen Stern , Christof Wetterich

A recent study of nonextensive phase transitions in nuclei and nuclear clusters needs a probability model compatible with the appropriate Hamiltonian. For magnetic molecules a representation of the evolution by a Markov process achieves the…

Statistical Mechanics · Physics 2009-11-11 Burhan Bakar , L. F. Lemmens

In some scenarios for the early universe, non-relativistic thermal dark matter chemically decouples from the thermal environment once the temperature drops well below the dark matter mass. The value at which the energy density freezes out…

High Energy Physics - Phenomenology · Physics 2025-01-09 Simone Biondini , Nora Brambilla , Andrii Dashko , Gramos Qerimi , Antonio Vairo

An introduction to nucleosynthesis, the creation of the elements in the big bang, in interstellar matter and in stars is given. The two--step process $^4$He(2n,$\gamma$)$^6$He and the reverse photodisintegration $^6$He($\gamma$,2n)$^4$He…

Nuclear Theory · Physics 2007-05-23 H. Oberhummer , W. Balogh , V. D. Efros , H. Herndl , R. Hofinger

We present a comprehensive study of s-process nucleosynthesis in 15, 20, 25, and 30 $\msun$ stellar models having solar-like initial composition. The stars are evolved up to ignition of central neon with a 659 species network coupled to the…

Astrophysics · Physics 2007-05-23 L. -S. The , M. F. El Eid , B. S. Meyer

We calculate finite-temperature corrections to the decay rate of a generic neutral (pseudo)scalar particle that decays into (pseudo)scalars or fermion-antifermion pairs. The ratio of the finite-temperature decay rate to the zero-temperature…

High Energy Physics - Phenomenology · Physics 2015-08-06 Chiu Man Ho , Robert J. Scherrer

In the primordial Universe, neutrino decoupling occurs only slightly before electron-positron annihilations, leading to an increased neutrino energy density with order $10^{-2}$ spectral distortions compared to the standard instantaneous…

Cosmology and Nongalactic Astrophysics · Physics 2020-02-19 Julien Froustey , Cyril Pitrou

The relationship among nuclear structure, the weak processes in nuclei, and astrophysics becomes quite apparent in supernova explosion and nucleosynthesis studies. In this brief article, I report on progress made in the last few years on…

Nuclear Theory · Physics 2009-11-06 D. J. Dean

The incredible thermo-mechanical properties of biological materials arise from the microscopic scale due to a complex hierarchical mechanism, regulated by microinstabilities at the molecular level. The description of such complex structures…

Biological Physics · Physics 2022-10-26 Luca Bellino

We investigate nucleosynthesis and element formation in the early universe in the framework of higher dimensional cosmology. For this purpose we utilize a previous solution of the present author, which may be termed as the generalized…

General Relativity and Quantum Cosmology · Physics 2015-05-14 S. Chatterjee

We study the big-bang nucleosynthesis (BBN) scenario with late-decaying exotic particles with lifetime longer than $\sim 1$ sec. With a late-decaying particle in the early universe, predictions of the standard BBN scenario can be…

Astrophysics · Physics 2010-04-05 Masahiro Kawasaki , Kazunori Kohri , Takeo Moroi

We point out that the relic densities of singlet (sterile) neutrinos of interest in viable warm and cold dark matter scenarios, depend on the characteristics of the QCD transition in the early universe. In the most promising of these dark…

Astrophysics · Physics 2009-11-07 Kevork N. Abazajian , George M. Fuller

A quantitative description of the properties of hot nuclear matter will be needed for the interpretation of the available and forthcoming astrophysical data, providing information on the post merger phase of a neutron star coalescence. We…

Nuclear Theory · Physics 2022-11-30 Lucas Tonetto , Omar Benhar

We study the effects of finite stellar temperatures on the oscillations of superfluid neutron stars. The importance of these effects is illustrated with a simple example of a radially pulsating general relativistic star. Two main effects…

Solar and Stellar Astrophysics · Physics 2011-06-07 E. M. Kantor , M. E. Gusakov