Palatini Approach to Modified Gravity: f(R) Theories and Beyond

TL;DR

This paper reviews recent developments in Palatini modified gravity theories, focusing on their applications to cosmology, astrophysics, and fundamental physics, highlighting the potential to address dark matter, dark energy, and quantum gravity issues.

Contribution

It provides a comprehensive overview of the Palatini approach to modified gravity, including recent research on cosmological and astrophysical phenomena beyond f(R) models.

Findings

Analysis of cosmic acceleration mechanisms

Tests of gravity in solar and laboratory environments

Insights into stellar structure and bouncing cosmologies

Abstract

We review the recent literature on modified theories of gravity in the Palatini approach. After discussing the motivations that lead to consider alternatives to Einstein's theory and to treat the metric and the connection as independent objects, we review several topics that have been recently studied within this framework. In particular, we provide an in-depth analysis of the cosmic speedup problem, laboratory and solar systems tests, the structure of stellar objects, the Cauchy problem, and bouncing cosmologies. We also discuss the importance of going beyond the f(R) models to capture other phenomenological aspects related with dark matter/energy and quantum gravity.