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Related papers: Particle acceleration and entropy considerations

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A Kappa distribution function applicable to systems comprising mixed fermions and bosons has been developed through the thermodynamic Gibbs potential utilizing the quantum versions of the Olbert kappa distributions. The generalised…

Plasma Physics · Physics 2025-05-19 Aakanksha Singh , Abhisek Kumar Singh , Punit Kumar

In three-dimensional electromagnetic configurations that result from unstable resistive tearing modes particles can efficiently be accelerated to relativistic energies. To prove this resistive magnetohydrodynamic simulations are used as…

Astrophysics · Physics 2009-11-07 Christoph Nodes , Guido T. Birk , Harald Lesch , R. Schopper

An important aspect of solar energetic particle (SEP) events is their source populations. Elemental abundance enhancements of impulsive SEP events, originating in presumed coronal reconnection episodes, can be fitted to steep power laws of…

Solar and Stellar Astrophysics · Physics 2024-03-12 Jin-Yi Lee , Stephen Kahler , John C. Raymond , Yuan-Kuen Ko

The Gibbs entropy of a macroscopic classical system is a function of a probability distribution over phase space, i.e., of an ensemble. In contrast, the Boltzmann entropy is a function on phase space, and is thus defined for an individual…

Statistical Mechanics · Physics 2020-07-01 Sheldon Goldstein , Joel L. Lebowitz , Roderich Tumulka , Nino Zanghi

The acceleration of energetic particles in astrophysical shear flows is analyzed. We show that in the presence of a non-relativistic gradual velocity shear, power law particle momentum distributions $f(p) \propto p^{-(3+\alpha)}$ may be…

Astrophysics · Physics 2009-11-10 F. M. Rieger , P. Duffy

This work presents a model for generating nonthermal power-law tails of particles' energy probability density functions in turbulent collisionless plasmas, applicable to both non-relativistic and relativistic scenarios. We propose that…

Plasma Physics · Physics 2026-05-05 Stanislav Boldyrev , Daniel Humphrey , Vadim Roytershteyn

When the difference between changes in energy and entropy at a given temperature is correlated with the ratio between the same changes in energy and entropy at zero average free energy of an ensemble of similar but distinct molecule-sized…

General Physics · Physics 2009-06-17 Petr Zimak , Silvia Terenzi , Peter Strazewski

The paper deals with the mechanism of particle creation in the framework of irreversible thermodynamics. The second order non-equilibrium thermodynamical prescription of Israel and Stewart has been presented with particle creation rate,…

General Relativity and Quantum Cosmology · Physics 2016-05-04 Subenoy Chakraborty , Subhajit Saha

Particle acceleration is one of the most significant features that are ubiquitous among space and cosmic plasmas. It is most prominent during flares in the case of the Sun, with which huge amount of electromagnetic radiation and high-energy…

Solar and Stellar Astrophysics · Physics 2014-05-15 Noriyuki Narukage , Masumi Shimojo , Taro Sakao

Scattering, during interplanetary transport in large, "gradual" solar energetic-particle (SEP) events, can cause element abundance enhancements or suppressions that depend upon the mass-to-charge ratio A/Q of the ions as an increasing…

Solar and Stellar Astrophysics · Physics 2016-01-21 Donald V. Reames

We are interested in electrons kinetics in a stellar atmosphere to validate or invalidate the usually accepted hypothesis of thermalisation of electrons. For this purpose, we calculate the velocity distribution function of electrons by…

Astrophysics · Physics 2007-05-23 L. Chevallier

We investigate kinetic entropy-based measures of the non-Maxwellianity of distribution functions in plasmas, i.e., entropy-based measures of the departure of a local distribution function from an associated Maxwellian distribution function…

Plasma Physics · Physics 2020-10-28 Haoming Liang , M. Hasan Barbhuiya , P. A. Cassak , O. Pezzi , S. Servidio , F. Valentini , G. P. Zank

The fast solar wind is a collisionless plasma permeated by plasma waves on many different scales. A plasma wave represents the natural interplay between the periodic changes of the electromagnetic field and the associated coherent motions…

Space Physics · Physics 2011-07-29 Daniel Verscharen , Eckart Marsch

Combining the equivalence between cosmological particle creation and an effective viscous fluid pressure with the fact that the latter represents a dynamical degree of freedom within the second-order Israel-Stewart theory for imperfect…

Astrophysics · Physics 2009-10-31 Winfried Zimdahl

The aim of this work is to analyze the entropy, entropy flux and entropy supply rate of granular fluids within the frameworks of the Boltzmann equation and continuum thermodynamics. It is shown that the entropy inequality for a granular gas…

Statistical Mechanics · Physics 2010-11-17 Gilberto M. Kremer

We examined energy spectrums of some particular systems of binary spins. It is shown that the configuration space can be divided into classes, and in the limit the energy distributions in these classes can be approximated by the normal…

Disordered Systems and Neural Networks · Physics 2015-05-14 Boris Kryzhanovsky , Leonid Litinskii

Small systems consisting of a few particles are increasingly technologically relevant. In such systems, an intense debate in microcanonical statistical mechanics has been about the correctness of Boltzmann's surface entropy versus Gibbs'…

Statistical Mechanics · Physics 2024-09-20 Ananth Govind Rajan

The emission mechanism during the prompt phase in gamma-ray bursts (GRBs) can be investigated through correlations between spectral properties. Here, we revisit the correlation relating the instantaneous flux, $F$, and the photon index…

High Energy Astrophysical Phenomena · Physics 2019-01-16 Felix Ryde , Hoi-Fung Yu , Hüsne Dereli-Bégué , Christoffer Lundman , Asaf Pe'er , Liang Li

Non-thermal electron populations are observed throughout the heliosphere. The relaxation of an electron beam is known to produce Langmuir waves which, in turn, may substantially modify the electron distribution function. As the Langmuir…

Solar and Stellar Astrophysics · Physics 2015-06-12 Heather Ratcliffe , Nicolas H. Bian , Eduard P. Kontar

We present a new approach to analyze homogeneous nucleation based on non-equilibrium thermodynamics. The starting point is the formulation of a Gibbs equation for the variations of the entropy of the system, whose state is characterized by…

Condensed Matter · Physics 2007-05-23 D. Reguera Lopez , J. M. Rubi , A. Perez-Madrid