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Lévy walk dynamics in an external harmonic potential
Pengbo Xu1, Tian Zhou1, Ralf Metzler2
1School of Mathematics and Statistics, Gansu Key Laboratory of Applied Mathematics and Complex Systems, Lanzhou University, Lanzhou 730000, P. R. China.
Lévy walks (LWs) equilibrate exponentially under confinement, exhibiting a bimodal stationary distribution. This research clarifies LW behavior near boundaries, resolving long-standing questions in anomalous diffusion.
Area of Science:
- Statistical Physics
- Complex Systems
- Anomalous Diffusion
Background:
- Lévy walks (LWs) are spatiotemporally coupled random processes modeling superdiffusion.
- They are observed in diverse phenomena, including heat conduction, light propagation, and biological/robotic motion.
- Understanding LW behavior under external potentials is crucial for their theoretical and applied relevance.
Purpose of the Study:
- To investigate the response of Lévy walks to an external harmonic potential.
- To characterize the equilibrium properties and stationary distributions of confined LWs.
- To generalize LWs to scenarios involving confining forces and boundaries.
Main Methods:
- Theoretical analysis of Lévy walk dynamics in a harmonic potential.
- Derivation of the stationary distribution for confined LWs.
- Investigation of boundary effects, specifically near a reflecting boundary at the origin.
Main Results:
- Demonstrated exponential equilibration for Lévy walks in a harmonic potential.
- Identified the possibility of a bimodal stationary distribution.
- Showed a horizontal slope of the stationary distribution near a reflecting boundary, distinguishing LWs from other superdiffusive processes.
Conclusions:
- Lévy walks exhibit predictable equilibration and stationary distributions under confinement.
- The findings generalize LWs to confining forces and resolve existing theoretical puzzles.
- The unique boundary behavior provides a new characteristic for identifying LWs in experimental systems.
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