English

Arithmetic oscillations of the chemical distance in long-range percolation on $\mathbb Z^d$

Probability 2024-06-27 v2 Combinatorics

Abstract

We consider a long-range percolation graph on Zd\mathbb Z^d where, in addition to the nearest-neighbor edges of Zd\mathbb Z^d, distinct x,yZdx,y\in\mathbb Z^d are connected by an edge independently with probability asymptotic to βxys\beta|x-y|^{-s}, for s(d,2d)s\in(d,2d), β>0\beta>0 and |\cdot| a norm on Rd\mathbb R^d. We first show that, for all but a countably many β>0\beta>0, the graph-theoretical (a.k.a. chemical) distance between typical vertices at |\cdot|-distance rr is, with high probability as rr\to\infty, asymptotic to ϕβ(r)(logr)Δ\phi_\beta(r)(\log r)^\Delta, where Δ1:=log2(2d/s)\Delta^{-1}:=\log_2(2d/s) and ϕβ\phi_\beta is a positive, bounded and continuous function subject to ϕβ(rγ)=ϕβ(r)\phi_\beta(r^\gamma)=\phi_\beta(r) for γ:=s/(2d)\gamma:=s/(2d). The proof parallels that in a continuum version of the model where a similar scaling was shown earlier by the first author and J. Lin. This work also conjectured that ϕβ\phi_\beta is constant which we show to be false by proving that (logβ)Δϕβ(\log\beta)^\Delta\phi_\beta tends, as β\beta\to\infty, to a non-constant limit which is independent of the specifics of the model. The proof reveals arithmetic rigidity of the shortest paths that maintain a hierarchical (dyadic) structure all the way to unit scales.

Keywords

Cite

@article{arxiv.2112.12365,
  title  = {Arithmetic oscillations of the chemical distance in long-range percolation on $\mathbb Z^d$},
  author = {Marek Biskup and Andrew Krieger},
  journal= {arXiv preprint arXiv:2112.12365},
  year   = {2024}
}

Comments

32 pages, 2 figures, typos corrected, proofs expanded