TRIPLE POMERON VERTEX IN THE LIMIT N-C -] INFINITY

In the hard pomeron theory with the number of colours N-c --> infinity the diffractive amplitude obtained in [3] is compared with the result s found for N-c= 3 in [1] and in the dipole approach in [5]. It is sho wn that the double pomeron exchange contribution can be substituted by an equivalent triple pomeron interaction term. After such a substitut ion the triple pomeron vertices in [1,3,5] essentially coincide. It is demonstrated that, in any form, the triple pomeron vertex is conforma l invariant. It is also shown that higher order densities in the dipol e approach do not involve 1 to k pomeron verteces with k > 2 but are r ather given by a set of pomeron fan diagrams with only a triple pomero n coupling.