English

Parabolic Anderson model on critical Galton-Watson trees in a Pareto environment

Probability 2022-02-18 v1

Abstract

The parabolic Anderson model is the heat equation with some extra spatial randomness. In this paper we consider the parabolic Anderson model with i.i.d. Pareto potential on a critical Galton-Watson tree conditioned to survive. We prove that the solution at time tt is concentrated at a single site with high probability and at two sites almost surely as tt \to \infty. Moreover, we identify asymptotics for the localisation sites and the total mass, and show that the solution u(t,v)u(t,v) at a vertex vv can be well-approximated by a certain functional of vv. The main difference with earlier results on Zd\mathbb{Z}^d is that we have to incorporate the effect of variable vertex degrees within the tree, and make the role of the degrees precise.

Keywords

Cite

@article{arxiv.2202.08636,
  title  = {Parabolic Anderson model on critical Galton-Watson trees in a Pareto environment},
  author = {Eleanor Archer and Anne Pein},
  journal= {arXiv preprint arXiv:2202.08636},
  year   = {2022}
}