Daniela Klammer (Vienna):

Generalized Feynman rules and Unitarity

Abstract:

In noncommutative field thoeries, where the deformation also involves time, an application of the Feynman rules worked out by Filk leads to a violation of unitarity. It is shown in an explicit calculation of the fish graph that unitarity is, however, preserved in the so called Interaction Point Time Ordering Perturbation Theory, which gives rise to generalized Feynman rules derived first by Denk and Schweda.