Non-minimally coupled quartic inflation with Coleman-Weinberg one-loop corrections in the Palatini formulation

Abstract

We discuss how the non-minimal coupling xi phi R-2 between the inflaton and the Ricci scalar affects the predictions of single field inflation models in the Palatini formalism. The inflaton field phi must interact with matter fields at the end of inflation in order to make a transition to the radiation dominated era. Interactions of the inflaton with other fields lead to radiative corrections to the inflationary potential. These radiative corrections can be explained at leading order by Coleman-Weinberg (CW) one-loop corrections. In this work, the effect of radiative corrections to the potential has been examined using two different prescriptions debated in the literature. Prescription I and Prescription II examine the coupling of the inflaton to bosons and fermions. We analyze the range of these coupling parameters for which the spectral index n(s) and the tensor-to-scalar ratio r are compatible with data taken by the Keck Array/BICEP2 and Planck collaborations. Finally, we show for all the considered potentials the behavior of the running of the spectral index alpha = dn(s)/d ln k as a function of kappa for selected xi values. (C) 2020 The Author(s). Published by Elsevier B.V.