English
Related papers

Related papers: Analytical results connecting stellar structure pa…

200 papers

Possible entropy constraints on particle acceleration spectra are discussed. Solar flare models invoke a variety of initial distributions of the primary energy release over the particles of the flare plasma -- ie., the partition of the…

Astrophysics · Physics 2011-05-23 John C Brown , Gregory Beekman , Norman Gray , Alexander L MacKinnon

The probability distribution function for thermodynamics and econophysics is obtained by solving an equilibrium equation. This approach is different from the common one of optimizing the entropy of the system or obtaining the state of…

General Physics · Physics 2007-05-23 Diego Saa

We have previously developed for nuclear cross-sections of therapeutic protons a calculation model, which is founded on the collective model as well as a quantum mechanical many particle problem to derive the S matrix and transition…

Medical Physics · Physics 2014-02-25 W. Ulmer

The prediction of stellar ($\gamma$,$\alpha$) reaction rates for heavy nuclei is based on the calculation of ($\alpha$,$\gamma$) cross sections at sub-Coulomb energies. These rates are essential for modeling the nucleosynthesis of so-called…

Nuclear Theory · Physics 2020-07-15 P. Mohr , Zs. Fülöp , Gy. Gyürky , G. G. Kiss , T. Szücs

We estimate energy spectra and fluxes at the Earth's surface of the cosmic and Galactic neutrino backgrounds produced by thermonuclear reactions in stars. The extra-galactic component is obtained by combining the most recent estimates of…

Astrophysics · Physics 2008-11-26 Cristiano Porciani , Silvia Petroni , Giovanni Fiorentini

The potential for reactive metal fuels to enhance the energetic output of high explosives has generated an enduring interest in the study of composite explosives. It has typically been demonstrated that added metal fuels can have little or…

As contrast to the Maxwellian distribution, equilibrium distribution of the second kind or turbulent equilibrium is shown to exist under tertiary molecular chaos hypothesis to replace the classical binary chaos by Boltzmann. It is expressed…

Chaotic Dynamics · Physics 2007-05-23 Shunichi Tsuge

The present work proposes a self-consistent reduced-order NLTE kinetic model for radiating plasmas such as are found in the outer layers of stellar atmospheres. Starting from the most up-to-date set of ab-initio and experimental data, the…

Solar and Stellar Astrophysics · Physics 2017-04-12 A. Munafo , N. Mansour , M. Panesi

Our current understanding of interstellar carbon fractionation hinges on the interpretation of astrochemical kinetic models. Yet, the various reactions included carry large uncertainties in their (estimated) rate coefficients, notably those…

Astrophysics of Galaxies · Physics 2021-03-24 C. M. R. Rocha , H. Linnartz

The primary aim of experimental nuclear astrophysics is to determine the rates of nuclear reactions taking place in stars in various astrophysical conditions. These reaction rates are important ingredient for understanding the elemental…

Nuclear Experiment · Physics 2019-03-27 Gy. Gyürky , Zs. Fülöp , F. Käppeler , G. G. Kiss , A. Wallner

A generalized method to calculate the excitation-energy dependent parity ratio in the nuclear level density is presented, using the assumption of Poisson distributed independent quasi particles combined with BCS occupation numbers. It is…

The properties of the Galactic supernova remnant SN 1006 are theoretically reanalysed. Nonlinear kinetic theory is used to determine the acceleration efficiency of cosmic rays (CRs) in the supernova remnant SN 1006. The known range of…

High Energy Astrophysical Phenomena · Physics 2011-03-22 E. G. Berezhko , L. T. Ksenofontov , H. J. Voelk

A recently introduced analytical model for the nuclear density profile[1] is implemented in the Extended Thomas-Fermi (ETF) energy density functional. This allows to (i) shed a new light on the issue of the sign of surface symmetry energy…

Nuclear Theory · Physics 2014-07-10 Francois Aymard , Francesca Gulminelli , Jérôme Margueron

We propose a general approach, named by us hyperstatistics, to treat complex systems, in which Boltzmann-Gibbs statistics breaks down in domains of the system. Hyperstatistics preserves the concavity of nonadditive $q$-entropy. We obtain…

Statistical Mechanics · Physics 2026-04-29 Lucas Squillante , Samuel M. Soares , Constantino Tsallis , Mariano de Souza

High-energy emission spectra from the outer atmospheres of late-type stars represent an important feature of the stellar activity in several contexts, such as the photoevaporation and photochemistry of planetary atmospheres or the modeling…

Solar and Stellar Astrophysics · Physics 2025-11-17 Antonio Maggio , Ignazio Pillitteri , Jorge Sanz-Forcada , Giuseppina Micela

In a series of papers, Saxena, Mathai, and Haubold (2002, 2004a, 2004b) derived solutions of a number of fractional kinetic equations in terms of generalized Mittag-Leffler functions which provide the extension of the work of Haubold and…

Classical Analysis and ODEs · Mathematics 2009-11-11 R. K. Saxena , A. M. Mathai , H. J. Haubold

We survey the current situation regarding chemical modelling of the synthesis of molecules in the interstellar medium. The present state of knowledge concerning the rate coefficients and their uncertainties for the major gas-phase processes…

Big-bang nucleosynthesis (BBN) is valuable as a means to constrain the physics of the early universe and it is the only probe of the radiation-dominated epoch. A fundamental assumption in BBN is that the nuclear velocity distributions obey…

Nuclear Theory · Physics 2020-06-29 Nishanth Sasankan , Atul Kedia , Motohiko Kusakabe , Grant J Mathews

We have developed a simple model to investigate the modifications of the hydrodynamics and non-equilibrium ionization X-ray emission in young supernova remnants due to nonlinear particle acceleration. In nonlinear, diffusive shock…

Astrophysics · Physics 2009-10-31 A. Decourchelle , D. C. Ellison , J. Ballet

The current status of optical potentials employed in the prediction of thermonuclear reaction rates for astrophysics in the Hauser-Feshbach formalism is discussed. Special emphasis is put on $\alpha$+nucleus potentials. A novel approach for…

Nuclear Theory · Physics 2007-05-23 T. Rauscher