Detection of transition times from single-particle-tracking trajectories

作者:Akimoto Takuma*; Yamamoto Eiji
来源:PHYSICAL REVIEW E, 2017, 96(5): 052138.
DOI:10.1103/PhysRevE.96.052138

摘要

In heterogeneous environments, the diffusivity is not constant but changes with time. It is important to detect changes in the diffusivity from single-particle-tracking trajectories in experiments. Here, we devise a novel method for detecting the transition times of the diffusivity from trajectory data. A key idea of this method is the introduction of a characteristic time scale of the diffusive states, which is obtained by a fluctuation analysis of the time-averaged mean square displacements. We test our method in silico by using the Langevin equation with a fluctuating diffusivity. We show that our method can successfully detect the transition times of diffusive states and obtain the diffusion coefficient as a function of time. This method will provide a quantitative description of the fluctuating diffusivity in heterogeneous environments and can be applied to time series with transitions of states.

  • 出版日期2017-11-28