The inflationary trispectrum

We calculate the trispectrum of the primordial curvature perturbation generated by an epoch of slow-roll in. ation in the early universe, and demonstrate that the non-Gaussian signature imprinted at horizon crossing is unobservably small, of order lambda NL less than or similar to r/50, where r < 1 is the tensor-to-scalar ratio. Therefore any primordial non-Gaussianity observed in future microwave background experiments is likely to have been synthesized by gravitational effects on superhorizon scales. We discuss the application of Maldacena's consistency condition to the trispectrum.