The Averaging Homotopy

Classical averaging is an asymptotic theory in the sense that it con- siders the problem of finding a limit for a sequence of differential systems. We present here another formulation that is based on an homotopy be- tween any two vectorfields. This formulation accounts both for classical averaging and for regular perturbations. It can also be used to justify the use of numerical windowed averaging schemes without any asymptotic imbedding.