English

Natural inflation in Palatini $F(R)$

General Relativity and Quantum Cosmology 2026-03-16 v4 Cosmology and Nongalactic Astrophysics High Energy Physics - Phenomenology

Abstract

F(R)F(R) Palatini gravity provides a robust framework for constructing viable inflationary potentials. In this study, we examine natural inflation and show that its consistency with observational data can be restored when the model is embedded within F(R)F(R) Palatini gravity, specifically for F(R)=R+αRnF(R) = R + \alpha R^n with 7/4n27/4 \lesssim n \leq 2. For completeness, we also demonstrate that models with n>2n > 2 do not yield comparable improvements, achieving partial agreement with the data only in the limit n2n \rightarrow 2.

Keywords

Cite

@article{arxiv.2511.20557,
  title  = {Natural inflation in Palatini $F(R)$},
  author = {N. Bostan and R. H. Dejrah and C. Dioguardi and A. Racioppi},
  journal= {arXiv preprint arXiv:2511.20557},
  year   = {2026}
}

Comments

13 pages, 6 figures, refs. added, matches the published version, acknowledgments updated