Module 1: Introduction
  Lecture 2: Existence, Uniqueness, and Wellposedness
 

 

Sufficient Conditions for Wellposedness

We shall now give a sufficient condition for wellposedness of an IVP and this is given in the following theorem:

Theorem: If satisfies a Lipschitz condition on

then is well-posed on with respect to all initial data.

Proof: We can show this by considering the perturbed problem

(1.10)

where and are the small perturbations. Let be the norm defined as .

Let . Here is the changed solution and is the true solution. Now subtracting (1.7) from (1.10), we get

and .