Abstract
A major goal of modern cosmology is the detection of -modes in the cosmic microwave background polarization originated from primordial gravitational waves. Their detection not only could provide substantial evidence for primordial inflation but also could shed light on its physical nature. Under the assumption of single-field slow-roll inflation, a set of conditions exist for the scalar and tensor parameters. In particular, given a constraint on the scalar spectral index , its running , its running of running , and the tensor-to-scalar ratio , constraints can be derived on the tensor spectral index , its running , its running of running , and its running of running of running . Using current bounds from the Planck 2015 and BICEP2 datasets and under the slow condition we found the following constraints at 95% C.L.: , , , and . Future measurements of the tensor spectrum could therefore be used to test these bounds and the slow-roll condition.
4 More- Received 14 February 2019
DOI:https://doi.org/10.1103/PhysRevD.99.123522
© 2019 American Physical Society