论文标题
随机重置的异质介质中的瞬时异常扩散
Transient anomalous diffusion in heterogeneous media with stochastic resetting
论文作者
论文摘要
我们研究了异质介质中的扩散过程,在这种介质中,颗粒随机地以恒定速率随机重置为初始位置。异质培养基是使用空间依赖性扩散系数对粒子位置的依赖性的。我们使用绿色函数方法来获得精确的解决方案,以实现粒子位置的概率分布和均方根位移。这些结果得到进一步比较,并与langevin方程的数值模拟一致。我们还研究了与此扩散过程相关的第一学期时间问题,并获得了平均第一学期时间的精确表达。我们的发现表明,该系统表现出非高斯分布,瞬态异常扩散(子或超扩散)和固定状态,同时依赖媒体异质性和重置速率。我们进一步证明,媒体异质性非繁琐地影响平均第一通道时间,从而产生了最低量显示最小值的最佳重置率。
We investigate a diffusion process in heterogeneous media where particles stochastically reset to their initial positions at a constant rate. The heterogeneous media is modeled using a spatial-dependent diffusion coefficient with a power-law dependence on particles' positions. We use the Green function approach to obtain exact solutions for the probability distribution of particles' positions and the mean square displacement. These results are further compared and agree with numerical simulations of a Langevin equation. We also study the first-passage time problem associated with this diffusion process and obtain an exact expression for the mean first-passage time. Our findings show that this system exhibits non-Gaussian distributions, transient anomalous diffusion (sub- or superdiffusion) and stationary states that simultaneously depend on the media heterogeneity and the resetting rate. We further demonstrate that the media heterogeneity non-trivially affect the mean first-passage time, yielding an optimal resetting rate for which this quantity displays a minimum.