Abstract
This paper, which is in two parts, examines the stability of the Cauchy problem for the Korteweg—deVries (KdV) equation. Let {vm(x)} with m = 1, 2, … be a sequence of functions with the limit function . Then this work considers under what conditions as m → ∞ the solution vm(x,t) of the KdV equation
with the initial condition
has as its limiting solution the function u0(x, t) which is the solution of the Kdv equation
with the initial condition
The five conditions to be placed on the sequence of initial functions vm(x) in order that the result is true are to be found in Theorem 5.1. They involve conditions on , an integral involving and a Wronskian involving Jost solutions of the Schrödinger equation.