English

Geodesics in planar Poisson roads random metric

Probability 2024-07-11 v1 Metric Geometry

Abstract

We study the structure of geodesics in the fractal random metric constructed by Kendall from a self-similar Poisson process of roads (i.e, lines with speed limits) in R2\mathbb{R}^2. In particular, we prove a conjecture of Kendall stating that geodesics do not pause en route, i.e, use roads of arbitrary small speed except at their endpoints. It follows that the geodesic frame of (R2,T)\left(\mathbb{R}^2,T\right) is the set of points on roads. We also consider geodesic stars and hubs, and give a complete description of the local structure of geodesics around points on roads. Notably, we prove that leaving a road by driving off-road is never geodesic.

Keywords

Cite

@article{arxiv.2407.07887,
  title  = {Geodesics in planar Poisson roads random metric},
  author = {Guillaume Blanc and Nicolas Curien and Jonas Kahn},
  journal= {arXiv preprint arXiv:2407.07887},
  year   = {2024}
}

Comments

57 pages, 14 figures. Comments are welcome!

R2 v1 2026-06-28T17:36:07.549Z