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arXiv 0712.0467nlin.CDcond-mat.stat-mech
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混沌与非混沌多粒子系统的输运性质

Transport properties in chaotic and non-chaotic many particles systems

Fabio Cecconi, Massimo Cencini, Angelo Vulpiani

摘要:

通过数值模拟和动力学理论论证,研究了布朗运动的两种确定性模型。第一个模型由一个重硬盘浸入稀薄气体中的小而轻的硬盘作为热浴。第二个是相同的,除了粒子的形状,现在是正方形。这两个系统的基本区别在于相互作用:硬核弹性碰撞使圆盘的动力学变得混沌,而正方形的动力学则不是。值得注意的是,这种差异并没有反映在两个系统的输运性质:模拟表明,扩散系数,速度相关性和响应函数的重杂质是在协议与动力学理论的混沌和非混沌模型。然而,弛豫到平衡对相互作用的类型非常敏感。这些观测结果被用来重新考虑和讨论与混沌、统计力学和扩散有关的一些问题。

英文摘要:

Two deterministic models for Brownian motion are investigated by means of numerical simulations and kinetic theory arguments. The first model consists of a heavy hard disk immersed in a rarefied gas of smaller and lighter hard disks acting as a thermal bath. The second is the same except for the shape of the particles, which is now square. The basic difference of these two systems lies in the interaction: hard core elastic collisions make the dynamics of the disks chaotic whereas that of squares is not. Remarkably, this difference is not reflected in the transport properties of the two systems: simulations show that the diffusion coefficients, velocity correlations and response functions of the heavy impurity are in agreement with kinetic theory for both the chaotic and the non-chaotic model. The relaxation to equilibrium, however, is very sensitive to the kind of interaction. These observations are used to reconsider and discuss some issues connected to chaos, statistical mechanics and diffusion.

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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