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arXiv · 1702.04602

Working directly with probabilities in quantum field theory

Robert Dickinson·Jeff Forshaw·Peter Millington
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Abstract

We present a novel approach to computing transition probabilities in quantum field theory, which allows them to be written directly in terms of expectation values of nested commutators and anti-commutators of field operators, rather than squared matrix elements. We show that this leads to a diagrammatic expansion in which the retarded propagator plays a dominant role. As a result, one is able to see clearly how faster-than-light signalling is prevented between sources and detectors. Finally, we comment on potential implications of this approach for dealing with infra-red divergences.

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Robert Dickinson, Jeff Forshaw, Peter Millington. 2017-02-15. Working directly with probabilities in quantum field theory. https://doi.org/10.1088/1742-6596/880/1/012041

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