English

Covering of an inner subset by the confined random walk

Probability 2025-11-13 v1

Abstract

We consider the simple random walk conditioned to stay forever in a finite domain DNZd,d3D_N \subset \mathbb{Z}^d, d \geq 3 of typical size NN. This confined walk is a random walk on the conductances given by the first eigenvector of the Laplacian on DND_N. On inner sets of DND_N, the trace of this confined walk can be approximated by tilted random interlacements, which is a useful tool to understand some properties of the walk. In this paper, we propose to study the cover time of inner subsets ΛN\Lambda_N of DND_N as well as the so-called late points of these subsets. If ΛN\Lambda_N contains enough late points, we obtain the asymptotic expansion of the covering time as cΛNd[logNloglogN+G]c_\Lambda N^d \big[ \log N - \log\log N + \mathcal{G} \big], with G\mathcal{G} a Gumbel random variable, as well as a Poisson repartition of these late points. The method we use is similar to Belius' work about the simple random walk on the torus, which displays the same asymptotics albeit without the loglogN\log \log N term. In the more general setting of ``ball-like'' ΛN\Lambda_N, we simply get the first term of the asymptotic expansion.

Keywords

Cite

@article{arxiv.2511.08817,
  title  = {Covering of an inner subset by the confined random walk},
  author = {Nicolas Bouchot},
  journal= {arXiv preprint arXiv:2511.08817},
  year   = {2025}
}

Comments

28 pages Keywords: random walk, confined walk, tilted interlacements, covering, Dirichlet eigenvector, coupling