相关论文: Incomplete-exclusion Statistical Mechanics in Non-…
The statistical mechanical investigation of Violent Relaxation of phase space elements of different densities first derived by Lynden-Bell (1967) is re-examined. It is found that the mass independence of the equations of motion of Violent…
We discuss the statistical mechanics of violent relaxation in stellar systems following the pioneering work of Lynden-Bell (1967). The solutions of the gravitational Vlasov-Poisson system develop finer and finer filaments so that a…
Violent relaxation process of spherical stellar systems is examined by numerical simulations of shell model. The collapse of uniform density sphere both with and without external force is investigated. It is found that time variation of…
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…
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…
Theory and simulations are used to study collisionless relaxation of a gravitational $N$-body system. It is shown that when the initial one particle distribution function satisfies the virial condition -- potential energy is minus twice the…
[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…
The term ``violent relaxation'' was coined by Donald Lynden-Bell as a memorable oxymoron describing how a stellar dynamical system relaxes from a chaotic initial state to a quasi-equilibrium. His analysis showed that this process is rapid,…
This talk provides a critical assessment of collisionless galactic dynamics, focusing on the interpretation and limitations of the collisionless Boltzmann equation and the physical mechanisms associated with collisionless relaxation.…
Collisionless and weakly collisional plasmas often exhibit non-thermal quasi-equilibria. Among these quasi-equilibria, distributions with power-law tails are ubiquitous. It is shown that the statistical-mechanical approach originally…
Plasmas whose Coulomb-collision rates are very small may relax on shorter time scales to non-Maxwellian quasi-equilibria, which, nevertheless, have a universal form, with dependence on initial conditions retained only via an infinite set of…
We present an analysis of two thermodynamic techniques for determining equilibria of self-gravitating systems. One is the Lynden-Bell entropy maximization analysis that introduced violent relaxation. Since we do not use the Stirling…
The statistical mechanical investigation of violent relaxation (Lynden-Bell 1967) is extended to indistinguishable objects. It is found that, coincidentally, the equilibrium distribution is the same as that obtained for classical objects.…
We examine an inconsistency in theories of violent-relaxation by Lynden-Bell and Nakamura. The inconsistency arises from the non-transitive nature of these theories: a system that under goes a violent-relaxation, relaxes and then upon an…
Large scale structures in the Universe, ranging from globular clusters to entire galaxies, are the manifestation of relaxation to out-of-equilibrium states that are not described by standard statistical mechanics at equilibrium. Instead,…
In $N$-body systems with long-range interactions mean-field effects dominate over binary interactions (collisions), so that relaxation to thermal equilibrium occurs on time scales that grow with $N$, diverging in the $N\to\infty$ limit.…
Violent relaxation during the collapse of a galaxy halo is known to be incomplete in realistic cases such as cosmological infall or mergers. We adopt a physical picture of strong but short lived interactions between potential fluctuations…
Finite size effects in the equilibrium phase space density distribution function are taken into account for alculations of the relaxation of collective motion in finite nuclei. Memory effects in the collision integral and the diffusivity…
A theoretical framework is presented which allows to quantitatively predict the final stationary state achieved by a non-neutral plasma during a process of collisionless relaxation. As a specific application, the theory is used to study…
Ultrafast optical excitation of metals induces a non-equilibrium energy distribution in the electronic system, with a characteristic step-structure determined by Pauli blocking. On a femtosecond timescale, electron-electron scattering…