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Related papers: Collisionless Relaxation of Stellar Systems

200 papers

We formulate the collisionless Boltzmann equation (CBE) for dense star clusters that lie within the radius of influence of a massive black hole in galactic nuclei. Our approach to these nearly Keplerian systems follows that of Sridhar and…

Astrophysics of Galaxies · Physics 2015-05-30 Jihad R. Touma , S. Sridhar

The first kinetic study of transient growth for a collisionless homogeneous Maxwellian plasma in a uniform magnetic field is presented. A system which is linearly stable may display transient growth if the linear operator describing its…

Plasma Physics · Physics 2009-03-13 Enrico Camporeale , David Burgess , Thierry Passot

[Abridged] N-body simulations of collisionless collapse have offered important clues to the construction of realistic stellar dynamical models of elliptical galaxies. Understanding this idealized and relatively simple process, by which…

Astrophysics · Physics 2009-11-10 M. Trenti , G. Bertin , T. S. van Albada

Gibbs statistical mechanics is derived for the Hamiltonian system coupling self-consistently a wave to N particles. This identifies Landau damping with a regime where a second order phase transition occurs. For nonequilibrium initial data…

Plasma Physics · Physics 2009-11-06 M. -C. Firpo , Y. Elskens

The collisionless Boltzmann equation (CBE) is a fundamental equation that governs the dynamics of a broad range of astrophysical systems from space plasma to star clusters and galaxies. It is computationally expensive to integrate the CBE…

Quantum Physics · Physics 2024-12-31 Soichiro Yamazaki , Fumio Uchida , Kotaro Fujisawa , Koichi Miyamoto , Naoki Yoshida

The relaxation of a weakly collisional plasma, which is of fundamental interest to laboratory and astrophysical plasmas, can be described by the Boltzmann-Poisson equations with the Lenard-Bernstein collision operator. We perform a…

Plasma Physics · Physics 2024-11-13 Uddipan Banik , Amitava Bhattacharjee

A classical long-range-interacting $N$-particle system relaxes to thermal equilibrium on time scales growing with $N$; in the limit $N\to \infty$ such a relaxation time diverges. However, a completely non-collisional relaxation process,…

Statistical Mechanics · Physics 2022-02-09 Alessandro Santini , Guido Giachetti , Lapo Casetti

A linearised kinetic equation describing electrostatic perturbations of a Maxwellian equilibrium in a weakly collisional plasma forced by a random source is considered. The problem is treated as a kinetic analogue of the Langevin equation…

Plasma Physics · Physics 2019-02-20 A. Kanekar , A. A. Schekochihin , W. Dorland , N. F. Loureiro

Anisotropic, non-thermal, and multi-temperature distributed particle momenta are commonly observed in collisionless space plasmas, such as the solar wind. Using Liouville's theorem, we argue that anisotropic compression or expansion of the…

Plasma Physics · Physics 2026-02-12 Torsten Enßlin , Christoph Pfrommer

Motivated by the recent interest in non-equilibrium phenomena in quantum many-body systems, we study strongly interacting fermions on a lattice by deriving and numerically solving quantum Boltzmann equations that describe their relaxation…

Quantum Physics · Physics 2019-12-10 Friedemann Queisser , Sebastian Schreiber , Peter Kratzer , Ralf Schützhold

We introduce a model of uncoupled pendula, which mimics the dynamical behavior of the Hamiltonian Mean Field (HMF) model. This model has become a paradigm for long-range interactions, like Coulomb or dipolar forces. As in the HMF model,…

Statistical Mechanics · Physics 2010-12-14 Pierre de Buyl , David Mukamel , Stefano Ruffo

A class of simple kinetic systems is considered, described by the 1D Vlasov-Landau equation with Poisson or Boltzmann electrostatic response and an energy source. Assuming a stochastic electric field, a solvable model is constructed for the…

Plasma Physics · Physics 2018-01-29 T. Adkins , A. A. Schekochihin

Spurious velocities arising from the imperfect offset of the undesired term at the discrete level are frequently observed in numerical simulations of equilibrium multiphase flow systems using the lattice Boltzmann equation (LBE) method. To…

Fluid Dynamics · Physics 2023-11-21 Long Ju , Peiyao Liu , Bicheng Yan , Jin Bao , Shuyu Sun , Zhaoli Guo

N-body simulations of collisionless collapse have offered important clues to the construction of realistic stellar dynamical models of elliptical galaxies. Such simulations confirm and quantify the qualitative expectation that rapid…

Astrophysics · Physics 2009-11-10 G. Bertin , M. Trenti

Placed slightly out of dynamical equilibrium, an isolated stellar system quickly returns towards a steady virialized state. We study this process of collisionless relaxation using the matrix method of linear response theory. We show that…

Astrophysics of Galaxies · Physics 2024-09-04 Simon Rozier , Raphaël Errani

The connection between domain relaxations at individual scales and the collective heterogeneous response in non-equilibrium systems is a topic of profound interest in recent times. In a model sys- tem of constantly driven oppositely charged…

Soft Condensed Matter · Physics 2016-12-16 Suman Dutta

We review and complete the kinetic theory of spatially inhomogeneous stellar systems when collective effects (dressing of the stars by their polarization cloud) are neglected. We start from the BBGKY hierarchy issued from the Liouville…

Astrophysics of Galaxies · Physics 2015-06-11 Pierre-Henri Chavanis

The particles model, the collision model, the polynomial development used for the equilibrium distribution, the time discretization and the velocity discretization are factors that let the lattice Boltzmann framework (LBM) far away from its…

N-body simulations of collisionless collapse have offered important clues to the construction of realistic stellar dynamical models of elliptical galaxies. Such simulations confirm and quantify the qualitative expectation that rapid…

Astrophysics · Physics 2007-05-23 M. Trenti , G. Bertin

Eulerian electrostatic kinetic simulations of unmagnetized plasmas (kinetic electrons and motionless protons) with high-frequency equilibrium perturbations have been employed to investigate the phase space free energy transfer across…

Plasma Physics · Physics 2023-10-12 G. Celebre , S. Servidio , F. Valentini