Abstract
The operator, which connects state vectors in interaction representation for different times, can be applied meaningfully to asymptotic values of state vectors if these limits exist. The conditions for this occurrence are stated for the simplest case. If the restriction resulting from the definition of the asymptotic values is respected, all operators are unambiguously unitary. A more general operator which can act on all state vectors, can be defined, but it is not unitary.
- Received 28 January 1954
DOI:https://doi.org/10.1103/PhysRev.94.1063
©1954 American Physical Society