“…a solution of (1.1) with a sufficiently small initial value (in some appropriate sense) is asymptotic as t → ∞ to a solution of the free Schrödinger equation. See [21,7,8,5,6,16,4]. On the other hand, if α ≤ 2 N , then low energy scattering cannot be expected, see [20,Theorem 3.2 and Example 3.3, p. 68] and [1].…”