Comb Model with Non-Static Stochastic Resetting and Anomalous Diffusion

Abstract

Nowadays, the stochastic resetting process is an attractive research topic in stochastic process. At the same time, a series of researches on stochastic diffusion in complex structures introduced ways to understand the anomalous diffusion in complex systems. In this work, we propose a non-static stochastic resetting model in the context of comb structure that consists of a structure formed by backbone in x axis and branches in y axis. Then, we find the exact analytical solutions for marginal distribution concerning x and y axis. Moreover, we show the time evolution behavior to mean square displacements (MSD) in both directions. As a consequence, the model revels that until the system reaches the equilibrium, i.e., constant MSD, there is a Brownian diffusion in y direction, i.e., 〈 ( Δ y ) 2 〉 ∝ t , and a crossover between sub and ballistic diffusion behaviors in x direction, i.e., 〈 ( Δ x ) 2 〉 ∝ t 1 2 and 〈 ( Δ x ) 2 〉 ∝ t 2 respectively. For static stochastic resetting, the ballistic regime vanishes. Also, we consider the idealized model according to the memory kernels to investigate the exponential and tempered power-law memory kernels effects on diffusive behaviors. In this way, we expose a rich class of anomalous diffusion process with crossovers among them. The proposal and the techniques applied in this work are useful to describe random walkers with non-static stochastic resetting on comb structure.

Keywords

• diffusion models
• anomalous diffusion
• non-static stochastic process
• comb model