中国物理B ›› 2011, Vol. 20 ›› Issue (4): 40502-040502.doi: 10.1088/1674-1056/20/4/040502
林方1, 包景东2
Lin Fang(林方)a)† and Bao Jing-Dong(包景东)b)
摘要: A generalized continuous time random walk model which is dependent on environmental damping is proposed in which the two key parameters of the usual random walk theory: the jumping distance and the waiting time, are replaced by two new ones: the pulse velocity and the flight time. The anomalous diffusion of a free particle which is characterized by the asymptotical mean square displacement <x2(t)>~tα is realized numerically and analysed theoretically, where the value of the power index α is in a region of 0 < α < 2. Particularly, the damping leads to a sub-diffusion when the impact velocities are drawn from a Gaussian density function and the super-diffusive effect is related to statistical extremes, which are called rare-though-dominant events.
中图分类号: (Random walks and Levy flights)