Celestial Feynman Rules for Scalars

Walker Melton

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arXiv · 2109.07462

Celestial Feynman Rules for Scalars

Walker Melton

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Abstract

Off-shell celestial amplitudes with both time-like and space-like external legs are defined. The Feynman rules for scalar amplitudes, viewed as a set of recursion relations for off-shell momentum space amplitudes, are transformed to the celestial sphere using the split representation. For four-point celestial amplitudes, the Feynman expansion is shown to be equivalent to a conformal partial wave decomposition, providing an interpretation of conformal partial wave expansion coefficients as integrals over off-shell three-point structures. A conformal partial wave decomposition for a simple four-point $s$-channel massless scalar celestial amplitude is derived.

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Walker Melton. 2021-09-15. Celestial Feynman Rules for Scalars. https://arxiv.org/abs/2109.07462

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