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The non-Gaussian tops and tails of diffusing boomerangs
Lyndon Koens1, Maciej Lisicki, Eric Lauga
1Department of Applied Mathematics and Theoretical Physics, University of Cambridge, UK. e.lauga@damtp.cam.ac.uk.
Soft Matter
|April 1, 2017
Summary
Tracking colloidal boomerangs reveals non-Gaussian diffusion patterns. Our model explains these anomalies by shifting reference points, showing how tracking location impacts statistical analysis of particle movement.
Area of Science:
- Soft Matter Physics
- Statistical Mechanics
- Colloidal Science
Background:
- Experiments show non-Gaussian tails in probability distribution functions for 2D passive diffusion of colloidal boomerangs.
- These deviations can lead to anomalous diffusion characteristics like mean drift.
Purpose of the Study:
- To develop a general theoretical explanation for the observed non-Gaussian diffusion patterns.
- To investigate the impact of the tracking reference point on diffusion statistics.
Main Methods:
- Calculating two-dimensional probability densities at the particle's center of mobility.
- Transforming these densities to a different reference point.
Main Results:
- The theoretical model accurately captures experimental results without fitting parameters.
- Demonstrates that one-dimensional probability distributions can exhibit strongly non-Gaussian tops.
- Highlights that the choice of tracking point significantly alters diffusion statistics.
Conclusions:
- The observed non-Gaussian diffusion is an artifact of the chosen tracking reference point.
- Departures from Gaussian statistics can invalidate common modeling techniques.
- Emphasizes the importance of carefully selecting tracking points in diffusion studies.
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