English

Genealogies under logistic growth

Probability 2025-11-11 v2

Abstract

We derive the asymptotic behaviour of the genealogy of a logistic branching process in the setting where the equilibrium population size is large. In three regimes on the tail of the offspring distribution we recover the Kingman, Beta(2α,α)\text{Beta}(2-\alpha, \alpha) and Bolthausen-Sznitman coalescents as a scaling parameter governing the population size is taken to infinity, the deduction going via the convergence in distribution of a modified lookdown construction. This resolves a question asked in arxiv:2501.16837 who studied the same population process forwards in time and showed convergence of the type frequency process to the corresponding Λ\Lambda-Fleming-Viot process in each regime.

Keywords

Cite

@article{arxiv.2509.05217,
  title  = {Genealogies under logistic growth},
  author = {Ruairi Garrett and Julio Ernesto Nava Trejo},
  journal= {arXiv preprint arXiv:2509.05217},
  year   = {2025}
}
R2 v1 2026-07-01T05:23:23.408Z