“…The use of the Strichartz estimates as an approximation device, as opposed to say energy estimates, is critical since the estimates obtained depend only upon the L 2 norm of the solution, which is conserved and independent of v. Thus, v functions as an asymptotic parameter; larger v means a shorter interaction phase and a better approximation of the solution by the linear flow. Theorem 2 combines this analysis with the inverse scattering method [11], [4], [3], [10]. The delta potential splits the incoming soliton into two waves which become single solitons.…”