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Related papers: Chaos, Regularity, and Noise in Self-Gravitating S…

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The initial conditions for Newtonian $N$-body simulations are usually generated by applying the Zel'dovich approximation to the initial displacements of the particles using an initial power spectrum of density fluctuations generated by an…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-23 Christian Fidler , Cornelius Rampf , Thomas Tram , Robert Crittenden , Kazuya Koyama , David Wands

We study, using both theory and simulations, a system of self-gravitating sheets. A new statistical mechanics theory - free of any adjustable parameters - is derived to quantitatively predict the final stationary state achieved by this…

Astrophysics of Galaxies · Physics 2013-05-14 Tarcísio Nunes Teles , Yan Levin , Renato Pakter

We develop here a new procedure within Einstein's theory of gravity to generate equilibrium configurations that result as the final state of gravitational collapse from regular initial conditions. As a simplification, we assume that the…

General Relativity and Quantum Cosmology · Physics 2015-05-28 Pankaj S. Joshi , Daniele Malafarina , Ramesh Narayan

Paper in honour of Freeman Dyson on the occasion of his 80th birthday. Normal N-body systems relax to equilibrium distributions in which classical kinetic energy components are 1/2 kT, but, when inter-particle forces are an inverse cubic…

Statistical Mechanics · Physics 2009-11-10 D. Lynden-Bell , R. M. Lynden-Bell

A relativistic self-gravitating equilibrium system with steady flow as well as spherical symmetry is discovered. The energy-momentum tensor contains the contribution of a current related to the flow and the metric tensor does an…

General Relativity and Quantum Cosmology · Physics 2026-01-08 Shuichi Yokoyama

In most books the Delaunay and Lagrange equations for the orbital elements are derived by the Hamilton-Jacobi method: one begins with the 2-body Hamilton equations, performs a canonical transformation to the orbital elements, and obtains…

Astrophysics · Physics 2009-11-07 Michael Efroimsky , Peter Goldreich

Integrations in fixed N-body realisations of smooth density distributions corresponding to a chaotic galactic potential can be used to derive reliable estimates of the largest (finite time) Lyapunov exponent X_S associated with an orbit in…

Astrophysics · Physics 2009-11-07 Henry E. Kandrup , Ioannis V. Sideris

Systems with long range interactions present generically the formation of quasi-stationary long-lived non-equilibrium states. These states relax to Boltzmann equilibrium following a dynamics which is not well understood. In this paper we…

Statistical Mechanics · Physics 2015-06-12 B. Marcos

The theory presented in this monograph establishes the first mathematically rigorous result on the global nonlinear stability of self-gravitating matter under small perturbations of an asymptotically flat, spacelike hypersurface of…

General Relativity and Quantum Cosmology · Physics 2017-07-04 Philippe G. LeFloch , Yue Ma

Relaxation processes in collisionless dynamics lead to peculiar behavior in systems with long-range interactions such as self-gravitating systems, non-neutral plasmas and wave-particle systems. These systems, adequately described by the…

Statistical Mechanics · Physics 2011-12-30 Pierre de Buyl , Pierre Gaspard

Possibilities emerging out of the dynamical evolutions of collapsing systems are addressed in this thesis through analytical investigations of the highly non-linear Einstein Field Equations. Studies of exact solutions and their properties,…

General Relativity and Quantum Cosmology · Physics 2017-09-07 Soumya Chakrabarti

I present the exact energy eigenstates and eigenvalues of a quantum many-body system of bosons on non-commutative space and in a harmonic oszillator confining potential at the selfdual point. I also argue that this exactly solvable system…

Mathematical Physics · Physics 2008-11-26 Edwin Langmann

In Newtonian gravity the final states of cold dissipationless collapses are characterized by several structural and dynamical properties remarkably similar to those of observed elliptical galaxies. Are these properties a peculiarity of the…

Astrophysics of Galaxies · Physics 2015-06-12 Pierfrancesco Di Cintio , Luca Ciotti , Carlo Nipoti

We study stochastic dynamics of an ensemble of N globally coupled excitable elements. Each element is modeled by a FitzHugh-Nagumo oscillator and is disturbed by independent Gaussian noise. In simulations of the Langevin dynamics we…

Statistical Mechanics · Physics 2009-11-11 M. Zaks , X. Sailer , L. Schimansky-Geier , A. Neiman

The Nordstr\"om-Vlasov system is a relativistic Lorentz invariant generalization of the Vlasov-Poisson system in the gravitational case. The asymptotic behavior of solutions and the non-linear stability of steady states are investigated. It…

Mathematical Physics · Physics 2009-11-13 Simone Calogero , Oscar Sanchez , Juan Soler

Chaos is present in most stellar dynamical systems and manifests itself through the exponential growth of small perturbations. Exponential divergence drives time irreversibility and increases the entropy in the system. A numerical…

Instrumentation and Methods for Astrophysics · Physics 2020-02-19 Tjarda Boekholt , Simon Portegies Zwart , Mauri Valtonen

Several advances in the theory of space-resolved viscoelasticity of liquids and other amorphous systems are discussed in the present paper. In particular, considering long-time regimes of stress relaxation in liquids we obtain the…

Soft Condensed Matter · Physics 2026-01-21 Jörg Baschnagel , Alexander N. Semenov

We study the behaviour of a specific system of relativistic elasticity in its own gravitational field: a static, spherically symmetric shell whose wall is of arbitrary thickness consisting of hyperelastic material. We give the system of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 CM Losert-Valiente Kroon

We consider an ensemble of mass collisionless particles, which interact mutually either by an attraction of Newton's law of gravitation or by an electrostatic repulsion of Coulomb's law, under a background downward gravity in a…

Analysis of PDEs · Mathematics 2024-12-25 Chanwoo Kim

Relativistic cosmological perturbation analyses can be made based on several different fundamental gauge conditions. In the pressureless limit the variables in certain gauge conditions show the correct Newtonian behaviors. We consider the…

Astrophysics · Physics 2007-05-23 J. Hwang , H. Noh