Spinor-Helicity Formalism for Massless Fields in AdS_{4}

Phys Rev Lett. 2019 Mar 15;122(10):101602. doi: 10.1103/PhysRevLett.122.101602.


In this Letter, we suggest a natural spinor-helicity formalism for massless fields in four-dimensional anti-de Sitter space (AdS_{4}). It is based on the standard realization of the AdS_{4} isometry algebra so(3,2) in terms of differential operators acting on sl(2,C) spinor variables. We start by deriving the anti-de Sitter counterpart of plane waves in flat space and then use them to evaluate simple scattering amplitudes. Finally, based on symmetry arguments, we classify all three-point amplitudes involving massless spinning fields. As in flat space, we find that the spinor-helicity formalism allows us to construct additional consistent interactions as compared to approaches employing Lorentz tensors.