Stokes Phenomena in Discrete Painlev\'e II

TL;DR

This paper investigates the asymptotic behavior of solutions to the discrete Painlevé II equation, revealing Stokes phenomena and providing a detailed exponential asymptotic analysis of the solutions' complex plane behavior.

Contribution

It applies exponential asymptotics to discrete Painlevé II, characterizing Stokes phenomena and identifying regions of valid asymptotic solutions in the complex plane.

Findings

Solutions are asymptotically pole-free in certain regions.

Stokes phenomena cause rapid switching in asymptotic behavior.

Behavior shares features with continuous Painlevé II solutions.

Abstract

We consider the asymptotic behaviour of the second discrete Painlev\'{e} equation in the limit as the independent variable becomes large. Using asymptotic power series, we find solutions that are asymptotically pole-free within some region of the complex plane. These asymptotic solutions exhibit Stokes phenomena, which is typically invisible to classical power series methods. We subsequently apply exponential asymptotic techniques to investigate such phenomena, and obtain mathematical descriptions of the rapid switching behaviour associated with Stokes curves. Through this analysis, we determine the regions of the complex plane in which the asymptotic approximations are valid, and find that the behaviour of these asymptotic solutions shares a number of features with the tronqu\'{e}e and tri-tronqu\'{e}e solutions of the second continuous Painlev\'{e} equation.