Effect of transitions in the Planck mass during inflation on primordial power spectra

Understand

We study the effect of sudden transitions in the effective Planck mass during inflation on primordial power spectra.

• Specifically, we consider models in which this variation results from the non-minimal coupling of a Brans-Dicke type scalar field.
• We find that the scalar power spectra develop features at the scales corresponding to those leaving the horizon during the transition.
• In addition, we observe that the tensor perturbations are largely unaffected, so long as the variation of the Planck mass is below the percent level.