Construction of the scattering matrix in the quantum theory of interacting fields

We consider the construction from a Lagrangian of chronologically ordered objects (τ-products) which define a relativistically covariant, unitary, and causal scattering matrix for locally noncommutative field interactions. We present and justify a method for constructing the τ-products which gives an explicit form of the scattering matrix. © 1989 Plenum Publishing Corporation.