Subleading soft theorem in arbitrary dimension from scattering equations
Burkhard U. W. Schwab, Anastasia Volovich
TL;DR
The paper uses the CHY scattering-equation framework to derive the subleading soft factors for Yang-Mills and gravity amplitudes in arbitrary dimensions, expanding the CHY integrals in the presence of a soft particle. It isolates the universal form of the subleading soft factor S^(1) for both theories by analyzing delta-function expansions and Pfaffian recursions, with spin contributions arising from the Pfaffian structure. The results reinforce the dimensional universality of the subleading soft theorems beyond four dimensions and illuminate how the angular-momentum components contribute within the CHY formalism. These findings connect CHY methods to known soft-theorem structures and motivate further exploration of symmetry principles and loop corrections in generic dimensions.
Abstract
We investigate the new soft graviton theorem recently proposed in arXiv:1404.4091. We use the CHY formula to prove this universal formula for both Yang-Mills theory and gravity scattering amplitudes at tree level in arbitrary dimension.