Abstract
It is explicitly shown that the nonvanishing spacelike or timelike contributions to the Feynman propagator of quantum-field theory do not reflect any violation of local causality, such as propagation faster than light. An experiment is proposed to test the causality of quantum-field theory by measuring the broadening of a very short light pulse. For these pulses theory predicts a nondissipative behavior, with the pulse broadening only stemming from preparation and measurement uncertainties.
- Received 13 September 1988
DOI:https://doi.org/10.1103/PhysRevA.39.2222
©1989 American Physical Society
