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Related papers: Dynamics of gas sphere under self-gravity

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We obtain a natural extension of the Vlasov-Poisson system for stellar dynamics to spaces of constant Gaussian curvature $\kappa\ne 0$: the unit sphere $\mathbb S^2$, for $\kappa>0$, and the unit hyperbolic sphere $\mathbb H^2$, for…

Analysis of PDEs · Mathematics 2016-04-20 Florin Diacu , Slim Ibrahim , Crystal Lind , Shengyi Shen

We take up the investigation we left in the future-work stack in Giordano \textit{et al.} [``Fluid statics of a self-gravitational isothermal sphere of van der Waals' gas,'' Phys. Fluids \textbf{36}, 056127 (2024)], in which we pointed out…

Astrophysics of Galaxies · Physics 2025-01-27 Domenico Giordano , Pierluigi Amodio , Felice Iavernaro , Francesca Mazzia

We consider a random diffusion dynamics for an infinite system of hard spheres of two different sizes evolving in $\mathbb{R}^d$, its reversible probability measure, and its projection on the subset of the large spheres. The main feature is…

Probability · Mathematics 2024-03-05 Myriam Fradon , Julian Kern , Sylvie Roelly , Alexander Zass

In this paper geology and planetology are considered using new conceptual basis of high-speed flow dynamics. Recent photo technics allow to see all details of a flow, 'cause the flow is static during very short time interval. On the other…

General Physics · Physics 2011-04-20 Yu. N. Bratkov

We present a class of solutions for a heat conducting fluid sphere, which radiates energy during collapse without the appearance of horizon at the boundary at any stage of the collapse. A simple model shows that there is no accumulation of…

General Relativity and Quantum Cosmology · Physics 2010-05-12 A. Banerjee , S. Chatterjee , N. Dadhich

We present a dark fluid model which contains the general linear equation of state including the gravitation term. The obtained spherical symmetric Euler equation and the continuity equation was investigated with the Sedov-type…

General Relativity and Quantum Cosmology · Physics 2022-09-08 Imre F. Barna , Mihály A. Pocsai , Gergely Gábor Barnaföldi

The self-oscillatory dynamics is considered as motion of a particle in a potential field in the presence of dissipation. Described mechanism of self-oscillation excitation is not associated with peculiarities of a dissipation function, but…

Adaptation and Self-Organizing Systems · Physics 2018-11-14 Vladimir V. Semenov

This paper aims to derive a definition of complexity for a dynamic spherical system in the background of self-interacting Brans-Dicke gravity. We measure complexity of the structure in terms of inhomogeneous energy density, anisotropic…

General Relativity and Quantum Cosmology · Physics 2021-01-06 M. Sharif , Amal Majid

The importance of roughness in the modeling of granular gases has been increasingly considered in recent years. In this paper, a freely evolving homogeneous granular gas of inelastic and rough hard disks or spheres is studied under the…

Soft Condensed Matter · Physics 2023-07-25 Alberto Megías , Andrés Santos

The dynamic impedance of a sphere oscillating in an elastic medium is considered. Oestreicher's formula for the impedance of a sphere bonded to the surrounding medium can be expressed simply in terms of three lumped impedances associated…

Soft Condensed Matter · Physics 2007-05-23 Andrew N. Norris

Radially symmetric shadow wave solutions to the system of multidimensional pressureless gas dynamics are introduced, which allow one to capture concentration of mass. The transformation to a one-dimensional system with source terms is…

Analysis of PDEs · Mathematics 2017-03-20 Marko Nedeljkov , Lukas Neumann , Michael Oberguggenberger , Manas Sahoo

We derive an expression for the expansion of outgoing null geodesics in spherical dust collapse and compute the limiting value of the expansion in the approach to singularity formation. An analogous expression is derived for the spherical…

General Relativity and Quantum Cosmology · Physics 2009-10-30 T. P. Singh

In this paper we consider a layer of incompressible viscous fluid lying above a flat periodic surface in a uniform gravitational field. The upper boundary of the fluid is free and evolves in time. We assume that a mass of surfactants…

Analysis of PDEs · Mathematics 2016-06-10 Chanwoo Kim , Ian Tice

We study a two-dimensional gas of inelastic rough spheres, driven on the rotational degrees of freedom. Numerical simulations are compared to mean-field (MF) predictions with surprisingly good agreement for strong coupling of rotational and…

Statistical Mechanics · Physics 2007-05-23 R. Cafiero , S. Luding , H. J. Herrmann

Most fully developed galaxies have a vivid spiral structure, but the formation and evolution of the spiral structure are still an enigma in astrophysics. In this paper, according to the standard Newtonian gravitational theory and some…

General Physics · Physics 2009-05-16 Ying-Qiu Gu

In recent works we developed a model of balanced gas flow where the momentum equation possesses an additional mean field forcing term, which originates from the hard sphere interaction potential between the gas particles. We demonstrated…

Fluid Dynamics · Physics 2021-10-20 Rafail V. Abramov

Thermal convection is observed in molecular dynamic simulation of a fluidized granular system of nearly elastic hard disks moving under gravity, inside a rectangular box. Boundaries introduce no shearing or time dependence, but the energy…

Statistical Mechanics · Physics 2009-10-31 Rosa Ramirez , Dino Risso , Patricio Cordero

Motivated by numerous geophysical applications, we have carried out laboratory experiments of a reactive (i.e. melting) solid sphere freely falling by gravity in a stratified environment, in the regime of large Reynolds ($Re$) and Froude…

Fluid Dynamics · Physics 2025-05-16 Ludovic Huguet , Victor Barge-Zwick , Michael Le Bars

An application of the ideas of the inertial confinement fusion process in the case of particles interacting at high energy is investigated. A possibility of the gas-liquid transition in the gas is considered using different approaches. In…

High Energy Physics - Phenomenology · Physics 2015-06-04 S. Bondarenko , K. Komoshvili

In this article we find explicit formulae for spherically symmetric solutions of the multidimensional zero-pressure gas dynamics system and its adhesion approximation. The asymptotic behaviour of the explicit solutions of the adhesion…

Analysis of PDEs · Mathematics 2014-04-29 Anupam Pal Choudhury , K. T. Joseph , Manas R. Sahoo