Inverse Soft Factors and Grassmannian Residues

TL;DR

This paper demonstrates a simplified approach to inverse soft factors in N=4 SYM using momentum twistor space, linking grassmannian residues to primitive leading singularities and providing explicit formulas.

Contribution

It introduces a new simple form for inverse soft factors in momentum twistor space and connects grassmannian residues to leading singularities with explicit expressions.

Findings

Inverse soft factors have a simple form in momentum twistor space.

Grassmannian residues correspond to primitive leading singularities.

Explicit formulas for residues in terms of momentum twistors are derived.

Abstract

The action of inverse soft factors on scattering amplitudes in N=4 SYM is shown to take a remarkably simple form in momentum twistor space. This is used to identify individual residues of the grassmannian with primitive leading singularities at NMHV and N^2MHV and to derive explicit expressions in terms of momentum twistors.