Abstract
Motivated by issues on inflation, a generalized modified gravity model is investigated, where the model Lagrangian is described by a smooth function of the Ricci scalar , the kinetic term of a scalar field . In particular, the one-loop effective action in the de Sitter background is examined on shell as well as off shell in the Landau gauge. In addition, the on-shell quantum equivalence of gravity in the Jordan and Einstein frames is explicitly demonstrated. Furthermore, we present applications related to the stability of the de Sitter solutions and the one-loop quantum correction to inflation in quantum-corrected gravity. It is shown that, for a certain range of parameters, the spectral index of the curvature perturbations can be consistent with the Planck analysis, but the tensor-to-scalar ratio is smaller than the minimum value within the error range of the BICEP2 result.
- Received 16 April 2014
DOI:https://doi.org/10.1103/PhysRevD.90.023525
© 2014 American Physical Society