COHERENT SOFT PHOTON STATES AND INFRA-RED DIVERGENCES. I. CLASSICAL CURRENTS,
Abstract
As a first step towards a treatment of soft photon processes which is free of infrared divergences and avoids the necessity of introducing a fictitious photon mass, the specification of asymptotic photon states belonging to non-Fock representations is discussed. As in the work of Chung, a basis consisting of generalized coherent states is used, but in contrast to his work, these states are rigorously defined in terms of von Neumann's infinite tensor product. It is shown that the states must be given an additional label which serves to distinguish various 'weekly equivalent' vectors, and which corresponds formally to an infinite phase factor. A non-separable Hilbert space H sub IR is defined (as a subspace of the infinite tensor product space) which may be regarded as the space of all possible asymptotic photon states. The interaction of the electromagnetic field with a prescribed classical current distribution is discussed, and it is shown that a unitary S operator all of whose matrix elements are finite may be defined on H sub IR. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1967
- Accession Number
- AD0655881
Entities
People
- T. W. B. Kibble
Organizations
- Imperial College London