Locality and Unitarity of Scattering Amplitudes from Singularities and Gauge Invariance.

  title={Locality and Unitarity of Scattering Amplitudes from Singularities and Gauge Invariance.},
  author={Nima Arkani-Hamed and Laurentiu Rodina and Jaroslav Trnka},
  journal={Physical review letters},
  volume={120 23},
We conjecture that the leading two-derivative tree-level amplitudes for gluons and gravitons can be derived from gauge invariance together with mild assumptions on their singularity structure. Assuming locality (that the singularities are associated with the poles of cubic graphs), we prove that gauge invariance in just n-1 particles together with minimal power counting uniquely fixes the amplitude. Unitarity in the form of factorization then follows from locality and gauge invariance. We also… 
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