Quintessential inflation in Palatini f (R) gravity

We investigate in detail a family of quintessential inflation models in the context of R + R-2 Palatini modified gravity. We find that successful inflation and quintessence are obtained with an inflaton scalar potential that is approximately quadratic in inflation and inverse quartic in quintessence. We show that corrections for the kination period due to Palatini modified gravity are subdominant, while the setup does not challenge constraints on modified gravity from Solar System observations and microscopic experiments, in contrast to the metric case. We obtain concrete predictions regarding primordial tensors to be probed in the near future.

Automated summary

We investigate a family of quintessential inflation models in R + R-2 Palatini modified gravity and find that successful inflation and quintessence are achievable with specific scalar potential forms. The corrections for the kination period due to Palatini modified gravity are subdominant, and the setup does not challenge constraints on modified gravity from Solar System observations and microscopic experiments. Concrete predictions regarding primordial tensors to be probed in the near future are obtained.