General hierarchy of charges at null infinity via the Todd polynomials

Abstract

We give a general procedure for constructing an extended phase space for Yang-Mills theory at null infinity, capable of handling the asymptotic symmetries and construction of charges responsible for subn-leading soft theorems at all orders. The procedure is coordinate and gauge-choice independent and can be fed into the calculation of both tree and loop-level soft limits. We find a hierarchy in the extended phase space controlled by the Bernoulli numbers arising in Todd genus computations. We give an example of a calculation at tree level, in radial gauge, where we also uncover recursion relations at all orders for the equations of motion and charges. Published by the American Physical Society 2025