A Test for Determining a Subdiffusive Model in Ergodic Systems from Single Trajectories

摘要

Experiments on particles' motion in living cells show that it is oftensubdiffusive. This subdiffusion may be due to trapping, percolation-likestructures, or viscoelatic behavior of the medium. While the models based ontrapping (leading to continuous-time random walks) can easily be distinguishedfrom the rest by testing their non-ergodicity, the latter two cases are harderto distinguish. We propose a statistical test for distinguishing between thesetwo based on the space-filling properties of trajectories, and prove itsfeasibility and specificity using synthetic data. We moreover present aflow-chart for making a decision on a type of subdiffusion for a broader classof models.