Anomalous particle diffusion influenced by angular heterogeneity

Abstract: A generalized persistent random walk (GPRW) model to study anomalous particle diffusion influenced by angular heterogeneity is presented. Consider the motion of a particle is composed of many consecutive straight line segments. At the end of each straight motion, the particle can switch to a new moving direction. Angular heterogeneity occurs when the probability of choosing a moving direction is non-uniformly distributed and influenced by surrounding environment and by the particle past conditions. Based on the model, we show that particles perform Gaussian Fickian diffusion with directional drifting in a memoryless system with spatial dependent angular heterogeneity. When the probability of maintaining the current moving direction is correlated with the particle speed, these particles perform Fickian diffusion, but their full distribution diverges from Gaussian. When the probability of maintaining te current moving direction is correlated with the historical moving distance, particles perform superdiffusion. The GPRW framework presented can be applied to study protein diffusion, cell migration and solute transport in complex heterogeneous environments.