CONSERVATION LAWS OF THE VARIABLE COEFFICIENT KdV AND MKdV EQUATIONS

Abstract

In this paper, by using the Miura's method, we study the infinite conservation laws of the variable coefficient KdV and MKdV equations with three arbitrary functions of t. The result points out that the conserved densities which have the structures completely similar to the con-stat coefficient KdV and MKdV equations depend only on one arbitrary function. The other two arbitrary functions are contained only in the corresponding fluxes.