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arXiv · 1902.02135

Causality and loop-tree duality at higher loops

Robert Runkel·Zoltán Szőr·Juan Pablo Vesga·Stefan Weinzierl
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Abstract

We relate a $l$-loop Feynman integral to a sum of phase space integrals, where the integrands are determined by the spanning trees of the original $l$-loop graph. Causality requires that the propagators of the trees have a modified $iδ$-prescription and we present a simple formula for the correct $iδ$-prescription.

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Robert Runkel, Zoltán Szőr, Juan Pablo Vesga, Stefan Weinzierl. 2019-06-26. Causality and loop-tree duality at higher loops. https://doi.org/10.1103/physrevlett.123.059902

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