Erratum: Causality and Loop-Tree Duality at Higher Loops [Phys. Rev. Lett. 122, 111603 (2019)].

This corrects the article DOI: 10.1103/PhysRevLett.122.111603.

Causality and Loop-Tree Duality at Higher Loops.

We relate an 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.