March 3, 2026Open Access

Beyond the Starobinsky model after ACT

Key Points

The model shows improved agreement with data after incorporating higher order corrections to the Ricci scalar.
Significant tension exists between the original Starobinsky model predictions and recent P-ACT-LB-BK18 data.
This analysis revisits the parameters influencing the inflationary model's dynamics, broadly impacting cosmological theories.
Understanding these adjustments may lead to important implications for post-inflationary dynamics in cosmology.

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. R 3 , R 4 , ⋅⋅⋅) can bring the model into better agreement with current data and impose nontrivial constraints on the post-inflationary dynamics.

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Discussion

Authors

Min Gi Park

Dhong Yeon Cheong

Seong Chan Park

Journals

Physics Letters B

Actions

Institutions

University of Chicago

Yonsei University

Korea Institute for Advanced Study

References and Citations

Connected Papers

Building similarity graph...

Analyzing shared references across papers

Beyond the Starobinsky model after ACT

Key Points

Abstract

Citation Network

Connected Papers

Discussion

Authors

Journals

Actions

Institutions

References and Citations

Citation Network

Connected Papers

Discussion

Cite this study