Intermittent many-body dynamics at equilibrium
Intermittent many-body dynamics at equilibrium
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DOI：
10.1103/physreve.95.060202
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发表时间：
2017-06-02
影响因子：
2.4
通讯作者：
Flach, S.
中科院分区：
文献类型：
--
作者：
Danieli, C.;Campbell, D. K.;Flach, S.
一个可观测量的平衡值定义了一个遍历和等分多体系统相空间中的流形。一个典型的轨迹，随着时间的推移，会无限频繁地穿过这个流形。我们使用这些穿孔来测量费米-帕斯塔-乌拉姆链的最低频率本征模的弛豫时间，以及随后的动态平衡的波动。在平衡的动态的特点是由幂律分布的偏移时间远离平衡，发散方差。长的漂移产生于粘动力学接近q呼吸子本地化在正常模式空间。测量指数可以预测到非遍历动力学的过渡。我们将我们的方法推广到Klein-Gordon晶格，其中粘性动力学是由于离散呼吸子定位在真实的空间。
The equilibrium value of an observable defines a manifold in the phase space of an ergodic and equipartitioned many-body system. A typical trajectory pierces that manifold infinitely often as time goes to infinity. We use these piercings to measure both the relaxation time of the lowest frequency eigenmode of the Fermi-Pasta-Ulam chain, as well as the fluctuations of the subsequent dynamics in equilibrium. The dynamics in equilibrium is characterized by a power-law distribution of excursion times far off equilibrium, with diverging variance. Long excursions arise from sticky dynamics close to q-breathers localized in normal mode space. Measuring the exponent allows one to predict the transition into nonergodic dynamics. We generalize our method to Klein-Gordon lattices where the sticky dynamics is due to discrete breathers localized in real space.