Palatini f(R) gravity as a fixed point

TL;DR

This paper investigates Palatini f(R) gravity, revealing it as a unique fixed point under a conformal transformation, which indicates fundamental issues that challenge its physical viability.

Contribution

It identifies Palatini f(R) gravity as a special fixed point in a conformal transformation, highlighting intrinsic problems that question its physical relevance.

Findings

Palatini f(R) gravity is a fixed point under conformal rescaling.

The fixed point nature indicates deep-rooted theoretical issues.

These issues suggest the theory may be unphysical.

Abstract

In the context of modified gravity, we point out how the Palatini version of these theories is singled out as a very special case corresponding to the unique fixed point of a transformation involving a special conformal rescaling of the metric. This mathematical peculiarity signals deeply rooted problems which make the theory unphysical.