S matrix unitarity in the dual invariant theory of vector particles

The work is the continuation of an article where a new version of the theory for a charged massive field of spin 1 has been suggested. Equations of motion, which are written down in a three-dimensional form, were used to describe a vector particle when including electromagnetic interaction. A theory with indefinite metrics has been considered. It is shown that in the vector theory version under investigation D invariance leads to the preservation of the probable interpretation of the theory. Zero equality of matrix elements of transition between states with different values of Dsub(eta) operator has been proved to prove unitarity of S matrix, Subspaces of the Gilbert space with different values of ''metric'' parity. are orthogonal which results in the S matrix unitarity with provision for the positiveness of the norm of states 1>μν