Non-Euclidean momentum space and the two-body problem

In the framework of quantum field theory with de Sitter momentum space an equation of quasipotential type is obtairmd for a two-particle system. The equation is solved in the quasictassical approximation. By analogy with the ordinary approach, largeangle scattering is regarded as scattering by a smooth quasipotential in the region of classically forbidden angles.