Regular celestial amplitudes

TL;DR

This paper introduces regular celestial amplitudes that are non-distributional and consistent with the celestial OPE, resolving paradoxes in conventional massless celestial amplitudes and proposing a revised CCFT correlator framework.

Contribution

The paper proposes regular celestial amplitudes that overcome distributional issues and align with celestial OPE, offering a new perspective on CCFT correlators.

Findings

Regular celestial amplitudes are non-distributional at tree level.

They are consistent with the celestial OPE.

They resolve the non-MHV paradox in celestial amplitudes.

Abstract

Conventional massless celestial amplitudes are distributional and fail to realize the celestial OPE -- most sharply in the non-MHV paradox, where OPEs predict nonzero celestial amplitudes with helicities $-{+}{+}+$ that are known to vanish at tree level. To resolve this, we introduce regular celestial amplitudes. We demonstrate that at tree-level, these amplitudes are non-distributional and, crucially, consistent with the celestial OPE. This suggests a revised dictionary: CCFT correlators are the regular, not conventional, celestial amplitudes.