Grup de Física Estadística, Departament de Física, Facultat de Ciències, Edifici Cc, Universitat Autònoma de Barcelona, 08193 Bellaterra (Barcelona), Spain.
Phys Rev E. 2019 Oct;100(4-1):042104. doi: 10.1103/PhysRevE.100.042104.
Random walks with stochastic resetting provides a treatable framework to study interesting features about central-place motion. In this work, we introduce noninstantaneous resetting as a two-state model being a combination of an exploring state where the walker moves randomly according to a propagator and a returning state where the walker performs a ballistic motion with constant velocity towards the origin. We study the emerging transport properties for two types of reset time probability density functions (PDFs): exponential and Pareto. In the first case, we find the stationary distribution and a general expression for the stationary mean-square displacement (MSD) in terms of the propagator. We find that the stationary MSD may increase, decrease or remain constant with the returning velocity. This depends on the moments of the propagator. Regarding the Pareto resetting PDF we also study the stationary distribution and the asymptotic scaling of the MSD for diffusive motion. In this case, we see that the resetting modifies the transport regime, making the overall transport subdiffusive and even reaching a stationary MSD, i.e., a stochastic localization. This phenomena is also observed in diffusion under instantaneous Pareto resetting. We check the main results with stochastic simulations of the process.
随机游走与随机重置为研究中央位置运动的有趣特征提供了一个可处理的框架。在这项工作中,我们将非瞬时重置作为一个两态模型引入,该模型由一个探索状态和一个返回状态组成,在探索状态中,随机游走者根据传播子随机移动,在返回状态中,随机游走者以恒定速度向原点进行弹道运动。我们研究了两种重置时间概率密度函数 (PDF) 的新兴传输特性:指数和帕累托。在第一种情况下,我们找到了固定分布和固定均方位移 (MSD) 的一般表达式,该表达式与传播子有关。我们发现,固定 MSD 可能随返回速度增加、减少或保持不变。这取决于传播子的矩。关于帕累托重置 PDF,我们还研究了扩散运动的固定分布和 MSD 的渐近标度。在这种情况下,我们看到重置改变了传输模式,使整体传输亚扩散,甚至达到固定 MSD,即随机定位。这种现象在瞬时帕累托重置下的扩散中也有观察到。我们通过该过程的随机模拟检查了主要结果。