Higher Curvature Corrections to Primordial Fluctuations in Slow-roll Inflation

Understand

We study higher curvature corrections to the scalar spectral index, the tensor spectral index, the tensor-to-scalar ratio, and the polarization of gravitational waves.

• We find that the higher curvature corrections can not be negligible in the dynamics of the scalar field, although they are energetically negligible.
• Indeed, it turns out that the tensor-to-scalar ratio could be enhanced and the tensor spectral index could be blue due to the Gauss-Bonnet term.
• We estimate the degree of circular polarization of gravitational waves generated during the slow-roll inflation.