Beyond the Starobinsky model after ACT
arXiv:2509.04105 · doi:10.1016/j.physletb.2026.140217
Abstract
We revisit higher order corrections to the Starobinsky inflationary model using the most recent P-ACT-LB-BK18 data, which exhibits a mild but definite tension with the predictions of the original model. Our results demonstrate how even small {higher order} deformations of the Ricci scalar (e.g. ) can bring the model into better agreement with current data and impose nontrivial constraints on the post-inflationary dynamics.
6 pages, 5 figures