Interpret the connection–hypermomentum pair in amplitude bases

Determine whether the connection–hypermomentum pair admits a direct interpretation in Carrollian or celestial amplitude bases.

Background

The paper argues that a boundary theory dual to four-dimensional asymptotically flat gravity must couple not only to the Carrollian metric and observer field but also to the independent radiative connection sector. The response to this sector is encoded in the hypermomentum, while Carrollian amplitudes naturally reside at null infinity.

The paper leaves unresolved whether this geometric pair has a direct formulation in Carrollian or celestial amplitude bases, which would connect the boundary variational description to scattering observables and amplitude-based formulations of flat-space holography.