KLT-like behaviour of inflationary graviton correlators

摘要

We use the spinor helicity formalism to study KLT-like relations for the inflation-ary graviton four-point correlation function. New features are observed in this correlation function compared to the graviton scattering amplitude in flat spacetime. After obtaining the general momentum dependence, collinear, squeezed and collapsed limits are considered to further study the features of the correlation function, and the relation to the corresponding flat space scattering amplitude.