Haag–Ruelle scattering theory as scattering theory in different state spaces

It is shown that Haag–Ruelle scattering theory can be naturally included in the scheme of abstract scattering theory with a pair of spaces. The wave operators in Haag–Ruelle theory are defined by the method of bilinear functionals. In the abstract theory, a number of criteria for the scattering operator to be trivial are found.