Scalar Perturbation Produced at the Pre-inflationary Stage in   Eddington-inspired Born-Infeld Gravity
  We investigate the scalar perturbation produced at the pre-inflationary stage driven by a massive scalar field in Eddington-inspired Born-Infeld gravity. The scalar power spectrum exhibits a peculiar rise for low $k$-modes. The tensor-to-scalar ratio can be significantly lowered compared with that in the standard chaotic inflation model in general relativity. This result is very affirmative considering the recent dispute on the detection of the gravitational wave radiation between PLANCK and BICEP2. 
Inyong Cho and Naveen K. Singh
gr-qc hep-th