By means of a kinematic analysis of tree level graviton amplitudes we find, at least through six points, that the reason of their decompositon as a sum over products of Yang-Mills amplitudes is on-shell gauge invariance and unitarity. As a by-product of our analysis we find nonlinear relations obeyed by Yang-Mills amplitudes. All our results are valid for arbitrary spacetime dimensions.
@article{arxiv.1910.13519,
title = {The origin of the KLT relations and nonlinear relations for Yang-Mills amplitudes},
author = {Luiz Antonio Barreiro and Ricardo Medina},
journal= {arXiv preprint arXiv:1910.13519},
year = {2020}
}
Comments
Some corrections done. Accepted for publication in PLB