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Related papers: Self-graviting Gas Spheres in Equilibrium State

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We investigate a relativistic self-interacting gas in the field of an external {\it pp} gravitational wave. Based on symmetry considerations we ask for those forces which are able to compensate the imprint of the gravitational wave on the…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Alexander B. Balakin , Winfried Zimdahl

We develop a general formalism to determine the statistical equilibrium states of self-gravitating systems in general relativity and complete previous works on the subject. Our results are valid for an arbitrary form of entropy but, for…

General Relativity and Quantum Cosmology · Physics 2020-12-24 Pierre-Henri Chavanis

Statistical equilibrium configurations are important in the physics of macroscopic systems with a large number of constituent degrees of freedom. They are expected to be crucial also in discrete quantum gravity, where dynamical spacetime…

General Relativity and Quantum Cosmology · Physics 2021-09-14 Isha Kotecha

Modeling the internal structure of self-gravitating solid and liquid bodies presents a challenge, as existing approaches are often limited to either overly simplistic constant-density approximations or more complex numerical equations of…

Earth and Planetary Astrophysics · Physics 2025-07-31 Bartosz Żbik , Andrzej Odrzywołek

We investigate spherically symmetric equilibrium states of the Vlasov-Poisson system, relevant in galactic dynamics. We recast the equations into a regular three-dimensional system of autonomous first order ordinary differential equations…

Mathematical Physics · Physics 2007-10-31 J. Mark Heinzle , Alan D. Rendall , Claes Uggla

In this paper, we present a "stellar dynamics" model of an infinite Universe, where matter distribution follows an inverse proportionality squared relationship with respect to the distance from the rotation center of galaxy clusters and…

General Physics · Physics 2025-07-10 E. Lopez Sandoval

We investigate insterstellar gas spheres by determining the metric functions, the material distribution, and the features of particle orbits in terms of stability and geodesics. An exact solution of the Einstein's equations for interstellar…

General Relativity and Quantum Cosmology · Physics 2017-08-21 Dániel Barta

A gas of atoms some of which are in excited electronic state is under consideration. Since the lifetime of an excited state is to great extent larger than the time required for establishing the equilibrium over translational degrees of…

Condensed Matter · Physics 2007-05-23 O. Derzhko , R. Levitskii , O. Chernyavskii

We report the results of self-gravitating simulations of spiral galaxies, modeled by stellar and gaseous components, developed to investigate in particular the role of dissipation in the evolution of galaxy disks. The gas disk is simulated…

Astrophysics · Physics 2007-05-23 S. Junqueira , F. Combes

We study systematically stationary solutions to the coupled Vlasov and Poisson equations which have `self-similar' or scaling symmetry in phase space. In particular, we find analytically {\it all} spherically symmetric distribution…

Astrophysics · Physics 2015-06-24 R. N. Henriksen , Lawrence M. Widrow

We explore various instability models for the onset of star formation in irregular galaxies. Critical gas densities are calculated for gravitational instabilities with a thin, pure-gas disk, and with a thick disk composed of gas and a…

Astrophysics · Physics 2009-10-30 Deidre A. Hunter , Bruce G. Elmegreen , Aomawa L. Baker

By minimizing free energy density, we show that the stellar core of a hydrogen burning star is not in a global thermodynamical equilibrium unless density, temperature, mass and composition assume given values. The core (as the solar…

Nuclear Theory · Physics 2009-11-11 F. Ferro , A. Lavagno , P. Quarati

The equilibrium state of a turbulent clumpy gas disk is analytically investigated. The disk consists of distinct self-gravitating clouds. Gravitational cloud-cloud interactions transfer energy over spatial scales and produce a viscosity,…

Astrophysics · Physics 2009-11-07 B. Vollmer , T. Beckert

A steady self-diffusion process in a gas of hard spheres at equilibrium is analyzed. The system exhibits a constant gradient of labeled particles. Neither the concentration of these particles nor its gradient are assumed to be small. It is…

Statistical Mechanics · Physics 2015-06-17 J. Javier Brey , M. J. Ruiz-Montero

Self-gravitating systems are expected to reach a statistical equilibrium state either through collisional relaxation or violent collisionless relaxation. However, a maximum entropy state does not always exist and the system may undergo a…

Statistical Mechanics · Physics 2009-11-07 P. H. Chavanis , C. Rosier , C. Sire

This paper is devoted to study the stability/instability of the expansionfree self gravitating source in the framework of Einstein Gauss-Bonnet gravity. The source has been taken as Tolman-Bondi model which is homogenous in nature. The…

General Relativity and Quantum Cosmology · Physics 2015-04-22 G. Abbas , S. Sarwar

Recently, we have shown that dynamically stable ergostar solutions (equilibrium neutron stars that contain an ergoregion) with a compressible and causal equation of state exist [A. Tsokaros, M. Ruiz, L. Sun, S. L. Shapiro, and K. Ury\=u,…

General Relativity and Quantum Cosmology · Physics 2020-04-08 Antonios Tsokaros , Milton Ruiz , Stuart L. Shapiro

The paper considers Euler-Poisson equations which govern the steady state of a self gravitating, rotating, axi-symmetric fluid under the additional assumption that it is incompressible and stratified. In this setting we show that the…

Analysis of PDEs · Mathematics 2022-05-02 Mayer Humi

We investigate the existence and the stability of spherically symmetric thermal equilibrium states of the self-gravitating many-particle system which satisfies the Einstein-Vlasov equations with a negative cosmological constant. While a…

General Relativity and Quantum Cosmology · Physics 2021-08-17 Hiroki Asami , Chul-Moon Yoo

We study the general properties of a spherically symmetric body described through the generalized Chaplygin equation of state. We conclude that such object, dubbed generalized Chaplygin dark star, should exist within the context of the…

Astrophysics · Physics 2009-11-13 O. Bertolami , J. Paramos