Violation of consistency relations and the protoinflationary transition
  If we posit the validity of the consistency relations, the tensor spectral index and the relative amplitude of the scalar and tensor power spectra are both fixed by a single slow roll parameter. The physics of the protoinflationary transition can break explicitly the consistency relations causing a reduction of the inflationary curvature scale in comparison with the conventional lore. After a critical scrutiny, we argue that the inflationary curvature scale, the total number of inflationary efolds and, ultimately, the excursion of the inflaton across its Planckian boundary are all characterized by a computable theoretical error. While these considerations ease some of the tensions between the Bicep2 data and the other satellite observations, they also demand an improved understanding of the protoinflationary transition whose physical features may be assessed, in the future, through a complete analysis of the spectral properties of the B mode autocorrelations. 
Massimo Giovannini
hep-th astro-ph.CO gr-qc hep-ph