The squeezed limit of the solid inflation three-point function

Understand

The recently proposed model of 'solid inflation' features a peculiar three-point function for scalar perturbations with an anisotropic, purely quadrupolar, squeezed limit.

• We confirm this result as well as the overall amplitude of the three point-function via an extremely simple computation, where we focus on the squeezed limit from the start and follow the standard logic adopted in deriving the consistency relations.
• Our system violates the consistency relations, but in the squeezed limit the three-point function can still be traded for a background-dependent two-point function, which is immediate to compute.
• Additionally, we use these simple methods to derive some new results - namely, certain squeezed limits of the three-point correlators involving vector and tensor perturbations as well.