Shadow Celestial Amplitude

Abstract

We study scattering amplitudes in the shadow conformal primary basis, which satisfies the same defining properties as the original conformal primary basis and has many advantages over it. The shadow celestial amplitudes exhibit locality manifestly on the celestial sphere, and behave like correlation functions in conformal field theory under the operator product expansion (OPE) limit. We study the OPE limits for three-point shadow celestial amplitude, and general 2 → n − 2 shadow celestial amplitudes from a large class of Feynman diagrams. In particular, we compute the conformal block expansion of the s-channel four-point shadow celestial amplitude of massless scalars at tree-level, and show that the expansion coefficients factorize as products of OPE coefficients.

Celestial locality and the Jacobi identity

“…Then the commutators of (leading) soft limits correspond to curvature on the conformal manifold of CCFTs. We leave the study of multiple insertions of soft shadows to the future, but we note that [29,[38][39][40] constitute preliminary work in this direction.…”