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arXiv 0712.1752cond-mat.stat-mech
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平均场哈密顿动力学中的非平衡相变

Out of equilibrium phase transitions in mean field Hamiltonian dynamics

Pierre-Henri Chavanis, Giovanni De Ninno, Duccio Fanelli, Stefano Ruffo

摘要:

具有长程相互作用的系统表现出向准定态(QSS)的短时弛豫,准定态的寿命随系统尺寸的增大而增大。本文以哈密顿平均场(HMF)模型为参照,对林登-贝尔的"剧烈弛豫“理论进行了评述。后者的结果在一个最大熵计划的水袋初始配置文件,预测存在的平衡相变}分离均匀(零磁化)从非均匀(非零磁化)的QSS。分析了初始条件的两种不同参数表示,讨论了相图的特点。在这两种表示中,我们发现一个二阶和一阶线的相变合并在一个三临界点。特别注意的是支付的条件存在和稳定的均相。

英文摘要:

Systems with long-range interactions display a short-time relaxation towards Quasi-Stationary States (QSSs), whose lifetime increases with system size. With reference to the Hamiltonian Mean Field (HMF) model, we here review Lynden-Bell's theory of ``violent relaxation''. The latter results in a maximum entropy scheme for a water-bag initial profile which predicts the presence of out-of-equilibrium phase transitions} separating homogeneous (zero magnetization) from inhomogeneous (non-zero magnetization) QSSs. Two different parametric representations of the initial condition are analyzed and the features of the phase diagram are discussed. In both representations we find a second order and a first order line of phase transitions that merge at a tricritical point. Particular attention is payed to the condition of existence and stability of the homogenous phase.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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