A stroll through the loop-tree duality

TL;DR

This paper reviews recent advances in the Loop-Tree Duality framework, highlighting its ability to represent multi-loop scattering amplitudes causally and to handle infrared singularities effectively.

Contribution

It provides an overview of new developments in LTD, including causal representations and dual counter-terms for infrared divergence cancellation.

Findings

Causal representation of multi-loop integrals achieved

Dual local counter-terms effectively cancel infrared singularities

Framework enhances the computation of scattering amplitudes

Abstract

The Loop-Tree Duality (LTD) theorem is an innovative technique to deal with multi-loop scattering amplitudes, leading to integrand-level representations over an Euclidean space. In this article, we review the last developments concerning this framework, focusing on the manifestly causal representation of multi-loop Feynman integrals and scattering amplitudes, and the definition of dual local counter-terms to cancel infrared singularities.