English

Different effects of external force fields on aging L\'{e}vy walk

Statistical Mechanics 2022-09-07 v1

Abstract

Aging phenomena have been observed in numerous physical systems. Many statistical quantities depend on the aging time tat_a for aging anomalous diffusion processes. This paper pays more attention to how an external force field affects the aging L\'{e}vy walk. Based on the Langevin picture of L\'{e}vy walk and generalized Green-Kubo formula, we investigate the quantities which include the ensemble- and time-averaged mean-squared displacements in both weak aging tatt_a\ll t and strong aging tatt_a\gg t cases, and compare them to the quantities in the absence of any force field. Two typical force fields, constant force FF and time-dependent periodic force F(t)=f0sin(ωt)F(t)=f_0\sin(\omega t), are considered for comparison. The generalized Einstein relation is also discussed in the case with constant force. We find that the constant force is the key of generating the aging phenomena and enhancing the diffusion behavior of aging L\'{e}vy walk, while the time-dependent periodic force is not. The different effects of the two kinds of forces on the aging phenomena of L\'{e}vy walk are verified by both theoretical analyses and numerical simulations.

Cite

@article{arxiv.2209.01916,
  title  = {Different effects of external force fields on aging L\'{e}vy walk},
  author = {Yao Chen and Xudong Wang},
  journal= {arXiv preprint arXiv:2209.01916},
  year   = {2022}
}
R2 v1 2026-06-28T00:44:12.650Z