English

Poly-logarithmic localization for random walks among random obstacles

Probability 2018-07-24 v3

Abstract

Place an obstacle with probability 1p1-p independently at each vertex of Zd\mathbb Z^d, and run a simple random walk until hitting one of the obstacles. For d2d\geq 2 and pp strictly above the critical threshold for site percolation, we condition on the environment where the origin is contained in an infinite connected component free of obstacles, and we show that the following \emph{path localization} holds for environments with probability tending to 1 as nn\to \infty: conditioned on survival up to time nn we have that ever since o(n)o(n) steps the simple random walk is localized in a region of volume poly-logarithmic in nn with probability tending to 1. The previous best result of this type went back to Sznitman (1996) on Brownian motion among Poisson obstacles, where a localization (only for the end point) in a region of volume to(1)t^{o(1)} was derived conditioned on the survival of Brownian motion up to time tt.

Keywords

Cite

@article{arxiv.1703.06922,
  title  = {Poly-logarithmic localization for random walks among random obstacles},
  author = {Jian Ding and Changji Xu},
  journal= {arXiv preprint arXiv:1703.06922},
  year   = {2018}
}

Comments

Exposition further improved. Accepted by Annals of Probability. 41 Pages, 5 figures

R2 v1 2026-06-22T18:51:31.668Z