Theory 10/Statistical Mechanics
Anomalous Diffusion Is Obstacles
The claim
The anomalous diffusion exponent of a particle in a crowded medium is set by the ratio of obstacle density to the particle's persistence length, not by the density alone.
01The mechanism
Obstacles deflect persistent motion; when the persistence length is long relative to obstacle spacing, the walk becomes subdiffusive in a predictable way.
02Predictions
- P1Exponent should collapse onto the ratio.
- P2Density alone should mispredict across particle sizes.
03Refutation
Exponent tracking density would remove the persistence term.