Inflation, BICEP2, and an interesting discrepancy with Planck
by
Prof.Lorenzo Sorbo
(UMass Amherst & TPT-CEA Paris)
→
Europe/Madrid
IFAE Seminar room (IFAE)
IFAE Seminar room
IFAE
Description
The BICEP2 collaboration has reported a strong B mode signal in the CMB polarization, which is well fit by a tensor-to-scalar ratio of r ~ 0.2. In this talk I will first discuss the implications of such a large value of r for inflationary model building, in particular in UV complete theories. Then I will move on to one intriguing discrepancy between the observed best fit value for r=0.2 obtained by BICEP2 and the upper bound r<0.11 quoted by Planck. I will discuss two scenarios where this discrepancy could be of primordial origin. The first scenario is based on a step in the amplitude of the primordial scalar perturbations, the second on an anticorrelation between scalar and tensor modes.