Related Experiment Videos
Necessary criterion for distinguishing true superdiffusion from correlated random walk processes.
G M Viswanathan1, E P Raposo, F Bartumeus
1Departamento de Física, Universidade Federal de Alagoas, Maceió-AL, Brazil. Gandhi@df.ufal.br
Summary
Distinguishing anomalous diffusion requires a new criterion. If a random walk appears diffusive beyond its correlation time, it cannot be superdiffusive, aiding real-world data interpretation.
Area of Science:
- Physics
- Statistical Mechanics
- Complex Systems
Background:
- Anomalous diffusion phenomena present interpretation challenges.
- Distinguishing scale-invariant superdiffusion from Markovian correlated random walks is difficult.
Purpose of the Study:
- Propose a criterion to differentiate between superdiffusive and Markovian correlated random walks.
- Demonstrate the criterion's utility in interpreting real-world data.
Main Methods:
- Estimate the correlation time (tau) of orientation persistence in general correlated random walks.
- Analyze the diffusive behavior of experimentally observed random walks relative to tau.
Main Results:
- A criterion is proposed to distinguish between superdiffusive and Markovian correlated random walks.
- If a random walk exhibits diffusive behavior on scales larger than tau, superdiffusion is unlikely.
- The criterion is identified as necessary but not sufficient for true superdiffusion.
Conclusions:
- The proposed criterion offers a method to interpret anomalous diffusion data.
- It aids in distinguishing complex random walk behaviors, particularly superdiffusion.
- Further validation is needed as the criterion is not a sufficient condition.