The tensor force and the Kowalski-Noyes representation for the t-matrix

A formulation of the Kowalski-Noyes representation of the t-matrix is developed using Weinberg's quasiparticle formalism. Such a representation leads to non-singular integral equations for the t-matrix. It also suggests a separable approximation to the t-matrix, which reduces the Faddeev equations to coupled equations in one continuous variable. This separable approximation satisfies the off-shell unitarity relation, and has the corre behavior in the neighborhood of bound-state and resonance energies. The formulation given allows for a treatment of tensor forces.