KdV and Almost Conservation Laws
Abstract
Description
This short survey paper is concerned with a new method to prove global well-posedness results for dispersive equations below energy spaces, namely $H^{1}$ for the Schrödinger equation and $L^{2}$ for the KdV equation. The main ingredient of this method is the definition of a family of what we call almost conservation laws. In particular we analyze the Korteweg-de Vries initial value problem and we illustrate in general terms how the ``algorithm'' that we use to formally generate almost conservation laws can be used to recover the infinitely many conserved integrals that make the KdV an integrable system.
15 pages. This paper will appear in the AMS Proceedings of the Conference on Harmonic Analysis held at Mt. Holyoke College, June 24 - July 5, 2001
15 pages. This paper will appear in the AMS Proceedings of the Conference on Harmonic Analysis held at Mt. Holyoke College, June 24 - July 5, 2001