Abstract
We investigate the possible implications of the measured value of the scalar tilt for the tensor-to-scalar ratio in slow-roll, single-field inflationary models. The measured value of the tilt satisfies , where is the number of -folds for observationally relevant scales. If this is not a coincidence and the scaling holds for different values of , it strongly suggests that either is as big as (a possibility in tension with the recent data), or smaller than and exponentially dependent on . A large region of the plane is not compatible with this scaling.
- Received 15 November 2015
DOI:https://doi.org/10.1103/PhysRevD.92.123528
© 2015 American Physical Society