arXiv:2309.16271 [math.PR]AbstractReferencesReviewsResources
Excursion theory for the Wright-Fisher diffusion
Paul A. Jenkins, Jere Koskela, Jaromir Sant, Dario Spano, Ivana Valentic
Published 2023-09-28Version 1
In this work, we develop excursion theory for the Wright-Fisher diffusion with recurrent mutation. Our construction is intermediate between the classical excursion theory where all excursions begin and end at a single point and the more general approach considering excursions of processes from general sets. Since the Wright-Fisher diffusion has two boundary points, it is natural to construct excursions which start from a specified boundary point, and end at one of two boundary points which determine the next starting point. In order to do this we study the killed Wright-Fisher diffusion, which is sent to a cemetery state whenever it hits either endpoint. We then construct a marked Poisson process of such killed paths which, when concatenated, produce a pathwise construction of the Wright-Fisher diffusion.