Loop-tree duality and quantum field theory in four dimensions

TL;DR

Loop-tree duality transforms virtual loop integrals into phase-space integrals, enabling four-dimensional calculations and offering insights into infrared singularities in quantum field theory.

Contribution

The paper reviews the loop-tree duality method and demonstrates its application to regularize Feynman integrals at the integrand level in four dimensions.

Findings

Finite contributions computed in four dimensions

Natural interpretation of infrared singularities

Unified treatment of real and virtual contributions

Abstract

Loop-tree duality allows to express virtual contributions in terms of phase-space integrals, thus leading to a direct comparison with real radiation terms. In this talk, we review the basis of the method and describe its application to regularize Feynman integrals. Performing an integrand-level combination of real and virtual terms, we obtain finite contributions that can be computed in four-dimensions. Moreover, this method provides a natural physical interpretation of infrared singularities, their origin and the way that they cancel in the complete computation.