Towards a Carrollian Description of Yang-Mills

TL;DR

This paper develops a null infinity-based Carrollian theory for Yang-Mills that reproduces all tree-level amplitudes, introducing a novel NMHV amplitude expression and linking bulk gauge fields to celestial sphere data.

Contribution

It presents a new Carrollian framework on null infinity for Yang-Mills, capturing all tree amplitudes and providing a novel explicit NMHV amplitude expression.

Findings

Recovers all MHV and NMHV tree amplitudes in Yang-Mills.

Introduces a new explicit expression for NMHV amplitude.

Outlines how to obtain arbitrary tree amplitudes from the theory.

Abstract

We provide a theory defined purely on null infinity that describes Yang-Mills in the Minkowski space bulk. The dynamical field of our model is the characteristic data of the bulk gauge field, and the action combines an electric branch Carrollian kinetic term with non-local interactions of MHV type that link different points on the celestial sphere. We explicitly show how this theory recovers all MHV and NMHV tree amplitudes in Yang-Mills, and outline how arbitrary tree amplitudes may be obtained from its Feynman diagram expansion. The detailed expression we find for the NMHV amplitude appears to be new.