# Observing quantum gravity in gravitational waves

Gravity can be embedded into a renormalizable theory by means of adding quadratic in curvature terms.

However, this at first leads to the presence of the Weyl ghost. It is possible to get rid of this ghost if the

locality assumption is weakened and the propagator of the graviton is represented by an entire function

of the d'Alembertian operator without new poles and zeros. Models of this type admit a cosmological

solution describing the R^2, or Starobinsky, inflation. We study graviton production after inflation in

However, this at first leads to the presence of the Weyl ghost. It is possible to get rid of this ghost if the

locality assumption is weakened and the propagator of the graviton is represented by an entire function

of the d'Alembertian operator without new poles and zeros. Models of this type admit a cosmological

solution describing the R^2, or Starobinsky, inflation. We study graviton production after inflation in