“…(F=F* is the gradient in R", r=|x| and a = (a 1 ,..., a n ) are multi-indices with |a|=a 1 + ---+a n ), and prove the existence ( [1], [2], [5], [9], [11]) and the completeness ( [10], [13]) of the modified wave operators As we see in [10] and [13], Y+(x, A) can be obtained from X + (£, f) by a kind of Legendre transformation in classical mechanics and are used to establish the completeness of W%. On the other hand, Y ± (x 9 A) are directly used in [11] to obtain another formulation of the modified wave operators.…”