Tensor non-Gaussianities from Non-minimal Coupling to the Inflaton

Understand

Tensor non-Gaussianity represents an important future probe of the physics of inflation.

• Inspired by recent works, we elaborate further on the possibility of significant primordial tensor non-Gaussianities sourced by extra fields during inflation.
• Unitarity constraints limit the impact of extra (spinning) particle content by means of a lower bound on the corresponding mass spectrum.
• For spin-2 particles, this takes the form of the well-known Higuchi bound.