Hybrid metric-Palatini gravity: General formalism and applications

It has been established that both metric and Palatini versions of f(R) gravity have interesting features but also manifest several downsides. A hybrid combination of theories, containing elements from both of these formalisms, turns out to be very successful in accounting for the observed phenomenology and it is able to avoid some drawbacks of the original approaches. Here, we explore the formulation of this hybrid metric-Palatini approach and its main achievements in passing the local tests and several applications to astrophysical and cosmological scenarios. More specifically, we present the weak-field limit, analyze the well-posedness of the Cauchy problem for the hybrid model and explore the viability of generalized hybrid metric-Palatini gravitational theories.

Automated summary

The hybrid metric-Palatini approach is a successful gravitational theory that combines the advantages of metric and Palatini versions and avoids some drawbacks. This article explores the formulation of this hybrid approach and its achievements in passing local tests and applications in astrophysics and cosmology.