English

Local time for run and tumble particle

Statistical Mechanics 2021-04-26 v1

Abstract

We investigate the local time (Tloc)(T_{loc}) statistics for a run and tumble particle in an one dimensional inhomogeneous medium. The inhomogeneity is introduced by considering the position dependent rate of the form R(x)=γxαlαR(x) = \gamma \frac{|x|^{\alpha}}{l^{\alpha}} with α0\alpha \geq 0. For α=0\alpha =0, we derive the probability distribution of TlocT_{loc} exactly which is expressed as a series of δ\delta-functions in which the coefficients can be interpreted as the probability of multiple revisits of the particle to the origin starting from the origin. For general α\alpha, we show that the typical fluctuations of TlocT_{loc} scale with time as Tloct1+α2+αT_{loc} \sim t^{\frac{1+\alpha}{2+\alpha}} for large tt and their probability distribution possesses a scaling behaviour described by a scaling function which we have computed analytically. In the second part, we study the statistics of TlocT_{loc} till the RTP makes a first passage to x=M (>0)x=M~(>0). In this case also, we show that the probability distribution can be expressed as a series sum of δ\delta-functions for all values of α (0)\alpha~(\geq 0) with coefficients appearing from appropriate exit problems. All our analytical findings are supported with the numerical simulations.

Keywords

Cite

@article{arxiv.2011.04716,
  title  = {Local time for run and tumble particle},
  author = {Prashant Singh and Anupam Kundu},
  journal= {arXiv preprint arXiv:2011.04716},
  year   = {2021}
}

Comments

18 pages, 9 figures

R2 v1 2026-06-23T20:01:43.016Z