Supergravity Embedding for Palatini-Formulated Inflation

Construct supergravity versions of inflationary models based on the Palatini formulation of gravity, or determine whether such supergravity embeddings exist.

Background

The paper discusses various inflationary frameworks—such as the Starobinsky model, Higgs inflation, and α-attractors—that have established supergravity realizations. It contrasts this with Palatini-formulated modified gravity models, which have recently shown compatibility with ACT data but are less explored from the viewpoint of supergravity embeddings.

The authors explicitly note that, unlike the previously discussed models with known supergravity generalizations, they are not aware of any supergravity versions for Palatini-based inflation. Establishing such an embedding would bridge Palatini-formulated inflation with the broader supergravity program that underlies many modern inflationary constructions.

References

This class of models is very interesting but somewhat less explored. In particular, all models discussed in this paper up to now have supergravity generalizations, but we are unaware of any supergravity versions of inflationary models based on the Palatini formulation.

— On the Present Status of Inflationary Cosmology  (2505.13646 - Kallosh et al., 19 May 2025) in Section “Inflationary models with n_s > 1−2/N_e,” Subsection “Chaotic inflation with nonminimal coupling to gravity,” footnote following Eq. (xi2)