Uniqueness from locality and BCFW shifts

Abstract

We introduce a BCFW shift which can be used to recursively build the full Yang-Mills tree-level amplitude as a function of polarization vectors. Furthermore, in line with the recent results of arXiv:1612.02797, we conjecture that the Yang-Mills tree-level scattering amplitude is uniquely fixed by locality and demanding the usual asymptotic behavior under a sufficient number of shifts. Unitarity therefore emerges from locality and constructability. We prove this statement at the leading order in the soft expansion.

13 pages; v2 typo fixed in eq. (2.1); v3: minor revision

References in corpus (3)

• New Relations for Gauge-Theory Amplitudes
• Locality and Unitarity from Singularities and Gauge Invariance
• Gravitons, Bose-symmetry, and Bonus-scaling

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• UV consistency conditions for CHY integrands
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