Running primordial perturbations: Inflationary Dynamics and Observational Constraints

Understand

Inflationary cosmology proposes that the early Universe undergoes accelerated expansion, driven, in simple scenarios, by a single scalar field, or inflaton.

• The form of the inflaton potential determines the initial spectra of density perturbations and gravitational waves.
• We show that constraints on the duration of inflation together with the BICEP3/Keck bounds on the gravitational wave background imply that higher derivatives of the potential are nontrivial with a confidence of 99%.
• Such terms contribute to the scale-dependence, or running, of the density perturbation spectrum.