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arXiv · 1601.07627

Core-Halo Quasi-Stationary States in the Hamiltonian Mean-Field Model

Eiji Konishi
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Abstract

A characteristic feature of long-range interacting systems is that they become trapped in a non-equilibrium and long-lived quasi-stationary state (QSS) during the early stages of their development. We present a comprehensive review of recent studies of the core-halo structure of QSSs, in the Hamiltonian mean-field model, which is a mean-field model of mutually coupled ferromagnetic XY spins located at a point, obtained by starting from various unsteady rectangular water-bag type initial phase-space distributions. The main result exposed in this review is that the core-halo structure can be described by the superposition of two independent Lynden-Bell distributions. We discuss the completeness of collisionless relaxation of this double Lynden-Bell distribution by using both of Lynden-Bell entropy and double Lynden-Bell entropy for the systems at low energies per particle.

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Eiji Konishi. 2016-01-28. Core-Halo Quasi-Stationary States in the Hamiltonian Mean-Field Model. https://doi.org/10.1142/s0217979216300073

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