+O 0 f 1/ I -iv +(n -3) /2 e -fly' I Iy IiA-nl2 X 32 Chapter 1. 2dr <..... 5) + 1/2) 111 I- ia -I f2 e (-u +if2)7TSgn1jf2. 4) . • Denote by X± the characteristic function of the halfaxis IR ±.

E(A)-I) to the lineal does not have poles on the line ImA = k +n12 (resp. 3). Therefore we can reason similarly to the proof of assertion et et 1). • Let Mp be the set of functions v from Co (Rn \ 0) subject to the condition v(i(n +q),q,) Pro p 0 0, q = 0, ... ,p. 3. The set Mp is dense in Hfi (Rn) for any nonnegative integer p, and for /3-s *- k +ni2, k = 0,1, .... P r o o f . We first verify that M 0 is dense. For an arbitrary function v E Co (Rn \ 0) we introduce the sequence {vd k= 1 for which vk(r,q,) = ev(kr,q,) if /3-s >n12 and vk(r,q,) = k-nv(k-1r,q,) if /3-s

Transversal operators and their special representations 1. A transversal operator. Let «P be positively homogeneous function of degree a on IR m \ 0 that is infinitely differentiable on Sm -I. We denote the operator of multiplication by «P by the same letter «P. 1) where F is the Fourier transform on IR m and u u= E Co (Rm,lR m - n). We denote, as §it the partial Fourier transform with respect to the variables We put 0 = r 2)/lr2)1, X = x(l)lr 2)1, Y = y(l)lr 2)1. By using the fact that «P is homogeneous we obtain that the quantity Ir2) l- a(A0(X Ir2) I-I, r2) is equal to before, by Xn+l, ···,Xm .