Fixation and stationary times for the $\Lambda$-Wright-Fisher process
Abstract
We study the fixation and stationary behavior of the Lambda-Wright-Fisher process with parent-independent mutation and finitely many types, a jump-diffusion model for allele frequency dynamics in large populations with potentially large offspring variance. Using a lookdown construction, we characterize the distribution of fixation times and the order of allele extinctions in the absence of mutations, and identify a strong stationary time in the presence of mutations. Our results include explicit expressions for the mean fixation and stationary times for the Wright-Fisher diffusion, and mean fixation times in the Beta-coalescent case. A key component of our approach is the analysis of the fixation line introduced by H\'enard in (Ann. Appl. Probab., 25:3007-3032, 2015). We extend this process to incorporate mutation, providing a unified framework for studying both fixation and equilibrium behavior.
Cite
@article{arxiv.2308.09218,
title = {Fixation and stationary times for the $\Lambda$-Wright-Fisher process},
author = {Airam Blancas and Adrián González Casanova and Sebastian Hummel and Sandra Palau},
journal= {arXiv preprint arXiv:2308.09218},
year = {2025}
}