Measure-Theoretical Description of Klein-Gordon Multiparticle States

Abstract

It is shown that a multiparticle state constructed from solutions of the Klein‐Gordon equation can be also described by a family of complex measures having simple properties. These measures are the expectation values for that state of products of projectors corresponding to the spectral decompositions of certain self‐adjoint operators. The results obtained are used in discussing the problem of defining quantized free fields at a point.