Magdziarz Marcin, Zorawik Tomasz
Faculty of Pure and Applied Mathematics, Hugo Steinhaus Center, Wroclaw University of Science and Technology, Wyspianskiego 27, 50-370 Wroclaw, Poland.
Phys Rev E. 2017 Feb;95(2-1):022126. doi: 10.1103/PhysRevE.95.022126. Epub 2017 Feb 22.
Aging can be observed for numerous physical systems. In such systems statistical properties [like probability distribution, mean square displacement (MSD), first-passage time] depend on a time span t_{a} between the initialization and the beginning of observations. In this paper we study aging properties of ballistic Lévy walks and two closely related jump models: wait-first and jump-first. We calculate explicitly their probability distributions and MSDs. It turns out that despite similarities these models react very differently to the delay t_{a}. Aging weakly affects the shape of probability density function and MSD of standard Lévy walks. For the jump models the shape of the probability density function is changed drastically. Moreover for the wait-first jump model we observe a different behavior of MSD when t_{a}≪t and t_{a}≫t.
许多物理系统都会出现老化现象。在这类系统中,统计特性[如概率分布、均方位移(MSD)、首次通过时间]取决于初始化和观测开始之间的时间跨度 (t_a)。在本文中,我们研究了弹道式 Lévy 游走以及两个密切相关的跳跃模型(先等待和先跳跃)的老化特性。我们明确计算了它们的概率分布和均方位移。结果表明,尽管这些模型有相似之处,但它们对延迟 (t_a) 的反应却大不相同。老化对标准 Lévy 游走的概率密度函数形状和均方位移的影响较弱。对于跳跃模型,概率密度函数的形状会发生巨大变化。此外,对于先等待跳跃模型,当 (t_a\ll t) 和 (t_a\gg t) 时,我们观察到均方位移有不同的行为。