Recently , BICEP2 measurements of the cosmic microwave background ( CMB ) B -mode polarization at degree angular scales has indicated the presence of tensor modes with a high tensor-to-scalar ratio of r = 0.2 when assuming nearly scale-invariant tensor and scalar spectra , although the signal may be contaminated by dust emission as implied by the recent Planck polarization data .
This result is in conflict with the Planck best-fit Lambda Cold Dark Model with r < 0.11 .
Due to the fact that inflaton has to be interacting with other fields so as to convert its potential energy into radiation to reheat the Universe , the interacting inflaton may result in a suppression of the scalar spectrum at large scales .
This suppression has been used to explain the observed low quadrupole in the CMB anisotropy .
In this paper , we show that a combination of the tensor modes measured by BICEP2 and the large-scale suppressed scalar modes contributes to the CMB anisotropy in such a way that the resultant CMB anisotropy and polarization power spectra are consistent with both Planck and BICEP2 data .
We also project our findings to cases in which r may become reduced in future CMB polarization measurements .