English

Oscillations of quenched slowdown asymptotics for ballistic one-dimensional random walk in a random environment

Probability 2015-09-02 v1

Abstract

We consider a one dimensional random walk in a random environment (RWRE) with a positive speed limnXnn=vα>0\lim_{n\to\infty}\frac{X_n}{n}=v_\alpha>0. Gantert and Zeitouni showed that if the environment has both positive and negative local drifts then the quenched slowdown probabilities Pω(Xn<xn)P_\omega(X_n < xn) with x(0,vα)x \in (0,v_\alpha) decay approximately like exp{n11/s}\exp\{-n^{1-1/s}\} for a deterministic s>1s > 1. More precisely, they showed that nγlogPω(Xn<xn)n^{-\gamma} \log P_\omega( X_n < x n) converges to 00 or -\infty depending on whether γ>11/s\gamma > 1-1/s or γ<11/s\gamma < 1-1/s. In this paper, we improve on this by showing that n1+1/slogPω(Xn<xn)n^{-1+1/s} \log P_\omega( X_n < x n) oscillates between 00 and -\infty, almost surely. This had previously been shown by Gantert only in a very special case of random environments.

Keywords

Cite

@article{arxiv.1509.00445,
  title  = {Oscillations of quenched slowdown asymptotics for ballistic one-dimensional random walk in a random environment},
  author = {Sung Won Ahn and Jonathon Peterson},
  journal= {arXiv preprint arXiv:1509.00445},
  year   = {2015}
}

Comments

24 pages, 1 figure