The phase transition for parking on Galton--Watson trees
Discrete analysis (2022)
We establish a phase transition for the parking process on critical Galton--Watson trees. In this model, a random number of cars with mean $m$ and variance $σ^{2}$ arrive independently on the vertices of a critical Galton--Watson tree with finite variance $Σ^{2}$ conditioned to be large. The cars go down the tree towards the root and try to park on empty vertices as soon as possible. We show a phase transition depending on $$ Θ:= (1-m)^2- Σ^2 (σ^2+m^2-m).$$ Specifically, when $m \leq 1$, if $ Θ>0,$ then all but (possibly) a few cars will manage to park, whereas if $Θ0$, then a positive fraction of the cars will not find a spot and exit the tree through the root. This confirms a conjecture of Goldschmidt and Przykucki.
@article{DAS_2022_a18,
author = {Nicolas Curien and Olivier H\'enard},
title = {The phase transition for parking on {Galton--Watson} trees},
journal = {Discrete analysis},
year = {2022},
language = {en},
url = {http://geodesic.mathdoc.fr/item/DAS_2022_a18/}
}
Nicolas Curien; Olivier Hénard. The phase transition for parking on Galton--Watson trees. Discrete analysis (2022). http://geodesic.mathdoc.fr/item/DAS_2022_a18/