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DOE OSTI · 1833717

The EFT-hedron

Arkani-Hamed, Nima·Huang, Tzu-Chen·Huang, Yu-tin
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Abstract

We re-examine the constraints imposed by causality and unitarity on the low-energy effective field theory expansion of four-particle scattering amplitudes, exposing a hidden “totally positive” structure strikingly similar to the positive geometries associated with grassmannians and amplituhedra. This forces the infinite tower of higher-dimension operators to lie inside a new geometry we call the “EFT-hedron”. We initiate a systematic investigation of the boundary structure of the EFT-hedron, giving infinitely many linear and non-linear inequalities that must be satisfied by the EFT expansion in any theory. We illustrate the EFT-hedron geometry and constraints in a wide variety of examples, including new consistency conditions on the scattering amplitudes of photons and gravitons in the real world.

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72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDSEffective Field TheoriesScattering Amplitudes

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Arkani-Hamed, Nima, Huang, Tzu-Chen, Huang, Yu-tin. 2021-05-27. The EFT-hedron. https://doi.org/10.1007/jhep05(2021)259

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