New Actions for Modified Gravity and Supergravity

TL;DR

This paper introduces extended f(R) gravity and supergravity models incorporating Weyl tensor dependence, aiming to bridge phenomenological theories with UV completion and superstring embedding, with applications in cosmology.

Contribution

It presents a novel extension of f(R) gravity and supergravity actions including Weyl tensor dependence, advancing towards UV completion and superstring theory integration.

Findings

New supergravity actions with Weyl tensor dependence.

Potential applications in cosmological perturbations.

Framework for embedding into superstring theories.

Abstract

We extend the f(R) gravity action by including a generic dependence upon the Weyl tensor, and further generalize it to supergravity by using the super-curvature (R) and super-Weyl (W) chiral superfields in N=1 chiral curved superspace. We argue that our (super)gravitational actions are the meaningful extensions of the phenomenological f(R) gravity and its locally supersymmetric generalization towards their UV completion and their embedding into superstring theories. The proposed actions can be used for study of cosmological perturbations and gravitational instabilities due to a nonvanishing Weyl tensor in gravity and supergravity.