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arXiv 1805.05892cond-mat.stat-mech
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具有排斥幂律相互作用粒子的过阻尼动力学

Overdamped dynamics of particles with repulsive power-law interactions

André A. Moreira, César M. Vieira, Humberto A. Carmona, José S. Andrade, Constantino Tsallis

摘要:

本文研究了过阻尼$D$维粒子系统通过短程幂律势$V(r)\sim r^{-λ}\;(λ/D>1)$排斥相互作用的动力学。我们证明了这样的系统服从非线性扩散方程,并且它们的定态极值为$q$ -广义非加性熵。在这里,我们专注于这些系统的动态演化。我们的第一原理$D=1,2$多体数值模拟(基于牛顿定律)证实了从非线性扩散方程的时间相关解获得的预测,并表明单粒子空间分布$P(x,t)$似乎遵循紧支持$q$ -高斯形式,具有$q=1-λ/D$。我们还计算了速度分布$P(v_x,t)$,有趣的是,它们遵循相同的$q$ -高斯形式(显然对$D=1$是精确的,对$D=2$也几乎是如此)。令人满意的匹配之间的连续描述和分子动力学模拟在一个更一般的,与时间相关的,框架整齐地证实了这样的想法,即本耗散系统确实代表合适的应用程序的$q$ -广义热统计理论。

英文摘要:

We investigate the dynamics of overdamped $D$-dimensional systems of particles repulsively interacting through short-ranged power-law potentials, $V(r)\sim r^{-λ}\;(λ/D>1)$. We show that such systems obey a non-linear diffusion equation, and that their stationary state extremizes a $q$-generalized nonadditive entropy. Here we focus on the dynamical evolution of these systems. Our first-principle $D=1,2$ many-body numerical simulations (based on Newton's law) confirm the predictions obtained from the time-dependent solution of the non-linear diffusion equation, and show that the one-particle space-distribution $P(x,t)$ appears to follow a compact-support $q$-Gaussian form, with $q=1-λ/D$. We also calculate the velocity distributions $P(v_x,t)$ and, interestingly enough, they follow the same $q$-Gaussian form (apparently precisely for $D=1$, and nearly so for $D=2$). The satisfactory match between the continuum description and the molecular dynamics simulations in a more general, time-dependent, framework neatly confirms the idea that the present dissipative systems indeed represent suitable applications of the $q$-generalized thermostatistical theory.

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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