English

Rotating random trees with Skorokhod's $M_1$ topology

Probability 2026-03-05 v2

Abstract

We extend the classical coding of measured R\mathbb R-trees by continuous excursion-type functions to c\`adl\`ag excursion-type functions through the notion of parametric representations. The main feature of this extension is its continuity properties with respect to the Gromov-Hausdorff-Prokhorov topology for R\mathbb R-trees and Skorokhod's M1M_1 topology for c\`adl\`ag functions. As a first application, we study the R\mathbb R-trees Tx(α)\mathcal T_{x^{(\alpha)}} encoded by excursions of spectrally positive α\alpha-stable L\'evy processes for α(1,2]\alpha \in (1,2]. In a second time, we use this setting to study the large-scale effects of a well-known bijection between plane trees and binary trees, the so-called rotation. Marckert has proved that the rotation acts as a dilation on large uniform trees, and we show that this remains true when the rotation is applied to large critical Bienaym\'e trees with offspring distribution attracted to a Gaussian distribution. However, this does not hold anymore when the offspring distribution falls in the domain of attraction of an α\alpha-stable law with α(1,2)\alpha \in (1,2), and instead we prove that the scaling limit of the rotated trees is Tx(α)\mathcal T_{x^{(\alpha)}}.

Keywords

Cite

@article{arxiv.2412.12023,
  title  = {Rotating random trees with Skorokhod's $M_1$ topology},
  author = {Antoine Aurillard},
  journal= {arXiv preprint arXiv:2412.12023},
  year   = {2026}
}

Comments

45 pages, 20 figures, minor reformulations in v2