Bootstrapping large graviton non-Gaussianities

Gravitational interferometers and cosmological observations of the cosmic microwave background offer us prospect to probe laws gravity in primordial universe. To study interpret these datasets we need know possible graviton non-Gaussianities. this end, derive most general tree-level three-point functions (bispectra) for a massless all orders derivatives, assuming scale invariance. Instead working with explicit Lagrangians, take bootstrap approach obtain our results using recently derived constraints from unitarity, locality choice vacuum. Since make no assumptions about de Sitter boosts, capture phenomenology large classes models such as effective field theory inflation solid inflation. We present formulae infinite number parity-even bispectra. Remarkably, parity-odd bispectra, show that unitarity allows only handful shapes: three graviton-graviton-graviton, scalar-graviton-graviton one scalar-scalar-graviton, which explicitly. These non-Gaussianities can be large, example inflation, therefore constitute concrete well-motivated target future observations.