Abstract
An integral representation is found for the matrix element, between given states, of the commutator of two field operators. The representation makes use of the information derivable from the local commutativity of the operators and from the mass spectrum of the fields. The representation was discovered by Jost and Lehmann and proved by them for the case of two fields of equal mass. It is here extended to the case of unequal masses.
The mathematical basis of this work is the fact that every function of a four-vector , with a Fourier transform which vanishes for space like , has a unique extension which is a solution of the wave equation in six dimensions.
- Received 26 February 1958
DOI:https://doi.org/10.1103/PhysRev.110.1460
©1958 American Physical Society