Perturbative gauge theory at null infinity
Perturbative gauge theory at null infinity
We describe a theory living on the null conformal boundary $\mathcal{I}$ of four-dimensional Minkowski space, the states of which include the radiative modes of Yang--Mills theory. The action of a Kac--Moody symmetry algebra on the correlators of these states leads to a Ward identity for asymptotic ``large'' gauge transformations which …