English
Related papers

Related papers: Comment on ``Nonextensive theory of dark matter an…

200 papers

In the framework of nonextensive statistical mechanics, the equilibrium structures of astrophysical self-gravitating systems are stellar polytropes, parameterized by the polytropic index n. By careful comparison to the structures of…

Astrophysics · Physics 2009-06-23 Chloé Féron , Jens Hjorth

Density profiles of simulated galaxy cluster-sized dark matter haloes are analysed in the context of a recently introduced nonextensive theory of dark matter and gas density distributions. Nonextensive statistics accounts for long-range…

Astrophysics · Physics 2009-11-11 T. Kronberger , M. P. Leubner , E. van Kampen

Pronounced core-halo patterns of dark matter and gas density profiles, observed in relaxed galaxies and clusters, were hitherto fitted by empirical power-laws. On the other hand, similar features are well known from astrophysical plasma…

Astrophysics · Physics 2009-11-11 M. P. Leubner

By a natural nonextensive generalization of the conservation of energy in the q-kinetic theory, we study the nonextensivity and the power-law distributions for the many-body systems with the self-gravitating long-range interactions. It is…

Statistical Mechanics · Physics 2015-08-10 Jiulin Du

We study the nonextensive parameter for the rotating astrophysical systems with power-law distributions, including both the rotating self-gravitating system and the rotating space plasma. We extend the equation of nonextensive parameter to…

Statistical Mechanics · Physics 2017-02-10 Haining Yu , Jiulin Du

It is shown, that self-gravitating systems can be classified by a dimensionless constant positive number $\kappa = S T / E$, which can be determined from the (global) values for the entropy, temperature and (total) energy. The Kerr-Newman…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Michael Petri

We consider a model where a light scalar field (with mass $\lesssim 30\, {\rm eV}$), conjectured to be dark matter, has a non-minimal coupling to gravity. In the non-relativistic limit, this new coupling introduces a self-interaction term…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-24 Lingyuan Ji

This paper studies sufficient conditions for deriving the kappa distribution in polytropic plasmas by an improved method compared with the previous work [R. Guo, Phys. Plasmas \textbf{27}, 122104 (2020)]. We find that the polytropic…

Plasma Physics · Physics 2024-09-05 Ran Guo

The density profiles and other quantities of physical interest for spherically symmetric systems are computed by assuming that a collisionless stellar gas may relax to the non-Gaussian power law distribution suggested by the nonextensive…

Astrophysics · Physics 2011-07-19 J. A. S. Lima , R. E. de Souza

The statistical mechanics of a cloud of particles interacting via their gravitational potentials is an old problem which encounters some issues when the traditional Boltzmann-Gibbs statistics is applied. In this article, we consider the…

Statistical Mechanics · Physics 2018-04-10 Lenin Escamilla-Herrera , Christine Gruber , Viridiana Pineda , Hernando Quevedo

In this work, we study self-gravitating objects that obey a polytropic equation of state in hyperbolic symmetry. Specifically, we describe in detail the steps to derive the Lane-Emden equation from the structure equations of the system. To…

General Relativity and Quantum Cosmology · Physics 2025-05-29 M. Carrasco-H , E. Contreras , E. Fuenmayor , P. León

We use physical constrains imposed from the H-Theorem and from the negative nature of the heat capacity of self-gravitating thermodynamically isolated systems to investigate some possible limits on the stellar polytrope index $n$ within the…

Astrophysics · Physics 2009-11-10 R. Silva , J. S. Alcaniz

The nonextensivity in a non-isothermal plasma system with the Coulombian long-range interactions is studied in the framework of Tsallis statistics. We present for first time a mathematical expression of the nonextensive parameter q based on…

Statistical Mechanics · Physics 2015-08-10 Jiulin Du

The non-relativistic self-gravitating gas in thermal equilibrium in the presence of a positive cosmological constant Lambda (dark energy) is investigated. The dark energy introduces a force pushing outward all particles with strength…

Astrophysics · Physics 2009-11-07 H. J. de Vega , J. A. Siebert

Cosmological N-body simulations have revealed many empirical relationships of dark matter halos, yet the physical origin of these halo properties still remains unclear. On the other hand, the attempts to establish the statistical mechanics…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Dong-Biao Kang , Ping He

By introducing the polytropic gas model of interacting dark energy, we obtain the equation of state for the polytropic gas energy density in a non-flat universe. We show that for even polytropic index by choosing $K>Ba^{\frac{3}{n}}$, one…

General Relativity and Quantum Cosmology · Physics 2014-11-20 K. Karami , S. Ghaffari , J. Fehri

Spatial intermittency in fully developed turbulence is an established feature of astrophysical plasma fluctuations and in particular apparent in the interplanetary medium by in situ observations. In this situation the classical…

Astrophysics · Physics 2017-08-02 M. P. Leubner , Z. Voros , W. Baumjohann

We explore an autonomous system analysis of dark energy models with interactions between dark energy and cold dark matter in a general systematic approach to cosmological fluids. We investigate two types of models such as local and…

General Relativity and Quantum Cosmology · Physics 2024-03-14 Parth Shah , Gauranga C. Samanta , Kazuharu Bamba , R. Myrzakulov

[abridged] In the dark matter (DM) halos embedding galaxies and galaxy systems the `entropy' K = \sigma^2 / \rho^{2/3} (a quantity that combines the radial velocity dispersion \sigma with the density \rho) is found from intensive N-body…

Astrophysics · Physics 2011-02-11 A. Lapi , A. Cavaliere

Self-gravitating systems are generally thought to behavior non-extensively due to the long-range nature of gravitational forces. We obtain a relation between the nonextensive parameter q of Tsallis statistics, the temperature gradient and…

Astrophysics · Physics 2015-08-10 Jiulin Du
‹ Prev 1 2 3 10 Next ›