J. Diff. Eqns. 199 (2004) 22-46
Ian Melbourne and Guido Schneider
Abstract
For ab > -1, stable time periodic solutions A(X,T)= Aq eiqX + i wq T $ are the locally preferred planform for the complex Ginzburg-Landau equation
AT = A + (1+ia) AXX - (1+ib) A|A|2 .
In order to describe the spatial global behavior, an evolution equation for the local wave number q can be derived formally. The local wave number q satisfies approximately a conservation law
qt = [h(q)]x .
It is the purpose of this paper to explain the extent to which the conservation law is valid by proving estimates for this formal approximation.