  We prove low frequency resolvent estimates and local energy decay for the
Schr{\"o}dinger equation in an asymptotically Euclidean setting. More
precisely, we go beyond the optimal estimates by comparing the resolvent of the
perturbed Schr{\"o}dinger operator with the resolvent of the free Laplacian.
This gives the leading term for the developpement of this resolvent when the
spectral parameter is close to 0. For this, we show in particular how we can
apply the usual commutators method for generalized resolvents and
simultaneously for different operators. Finally, we deduce similar results for
the large time asymptotics of the corresponding evolution problem.
