Abstract
We consider Lévy flights subject to external force fields. This anomalous transport process is described by two approaches, a Langevin equation with Lévy noise and the corresponding generalized Fokker-Planck equation containing a fractional derivative in space. The cases of free flights, constant force, and linear Hookean force are analyzed in detail, and we corroborate our findings with results from numerical simulations. We discuss the non-Gibbsian character of the stationary solution for the case of the Hookean force, i.e., the deviation from Boltzmann equilibrium for long times. The possible connection to Tsallis’s q statistics is studied.
- Received 14 October 1998
DOI:https://doi.org/10.1103/PhysRevE.59.2736
©1999 American Physical Society