Hierarchically Coupled Ornstein–Uhlenbeck Processes for Transient Anomalous Diffusion

Autor: Jingyang Wang, Nikolaos K. Voulgarakis
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Physics, Vol 6, Iss 2, Pp 645-658 (2024)
Druh dokumentu: article
ISSN: 2624-8174
DOI: 10.3390/physics6020042
Popis: The nonlinear dependence of the mean-squared displacement (MSD) on time is a common characteristic of particle transport in complex environments. Frequently, this anomalous behavior only occurs transiently before the particle reaches a terminal Fickian diffusion. This study shows that a system of hierarchically coupled Ornstein–Uhlenbeck equations is able to describe both transient subdiffusion and transient superdiffusion dynamics, as well as their sequential combinations. To validate the model, five distinct experimental, molecular dynamics simulation, and theoretical studies are successfully described by the model. The comparison includes the transport of particles in random optical fields, supercooled liquids, bedrock, soft colloidal suspensions, and phonons in solids. The model’s broad applicability makes it a convenient tool for interpreting the MSD profiles of particles exhibiting transient anomalous diffusion.
Databáze: Directory of Open Access Journals
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