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Résumé |
Celestial amplitudes compute 4D scattering matrices in a basis of boost, rather
than conventional energy-momentum eigenstates. In this talk I will show how UV and
IR properties of quantum field theory and quantum gravity translate into
constraints on the analytic structure of celestial amplitudes. We will see, for
example, that the soft UV behavior of quantum gravity amplitudes implies that
four-point celestial amplitudes are meromorphic functions in the complex boost
weight plane with poles at negative integers. Moreover, the residues of these
poles are related to couplings in the low-energy effective field theory. Finally,
I will show that soft-hard factorization in momentum space maps to factorization
of celestial amplitudes and comment on some implications of these results. |
