Speaker
Dr
Peter Millington
(University of Manchester and IPPP, Durham University)
Description
In arXiv: 1312.3871, we introduce a way to compute transition amplitudes in quantum field theory for scatterings between sources and detectors, that is scatterings over finite space-time domains. Our amplitudes are manifestly causal, by which we mean that the source and detector are always linked by a connected chain of retarded propagators. We illustrate how these amplitudes may be obtained from a path-integral representation that closely resembles the in-in formalism of thermal field theory, introduced by Schwinger and Keldysh. Finally, we prove the tree-level equivalence of these amplitudes with the S-matrix and comment on potential deviations at the level of loops.
Primary author
Dr
Peter Millington
(University of Manchester and IPPP, Durham University)
