Scattering matrices for the quantum n body problem

Let H be a generalized N body Schrodinger operator with very short range potentials. Using Melrose's scattering calculus, it is shown that the free channel 'geometric' scattering matrix, defined via asymptotic expansions of generalized eigenfunctions of H, coincides (up to normalization) with the free channel 'analytic' scattering matrix defined via wave operators. Along the way, it is shown that the free channel generalized eigenfunctions of Herbst-Skibsted and Jensen-Kitada coincide with the plane waves constructed by Hassell and Vasy and if the potentials are very short range.