Generalized Master Equation for Space-Time Coupled Continuous Time Random Walk
Jian Liu1,2**, Bao-He Li1, Xiao-Song Chen2
1School of Science, Beijing Technology and Business University, Beijing, 100048 2CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190
Abstract:The generalized master equation for the space-time coupled continuous time random walk is derived analytically, in which the space-time coupling is considered through the correlated function $g(t) \sim t^{\gamma}$, $0 \le \gamma < 2$, and the probability density function $\omega(t)$ of a particle's waiting time $t$ follows a power law form for large $t$: $\omega(t) \sim t^{-(1+\alpha)}$, $0 < \alpha < 1$. The results indicate that the expressions of the generalized master equation are determined by the correlation exponent $\gamma$ and the long-tailed index $\alpha$ of the waiting time. Moreover, the diffusion results obtained from the generalized master equation are in accordance with the previous known results and the numerical simulation results.