Scalar-Tensor gravity with system-dependent potential and its relation with Renormalization Group extended General Relativity

TL;DR

This paper introduces a new class of scalar-tensor gravity theories with flexible potentials, demonstrating their relation to Renormalization Group extended gravity and proposing a covariant scale setting for fluids.

Contribution

It presents a novel scalar-tensor framework with adaptable potentials that encompasses Renormalization Group extended gravity, along with a covariant scale setting method.

Findings

Extended scalar-tensor theories include RG extended gravity as a special case

A covariant Renormalization Group scale setting for relativistic fluids is proposed

The new framework broadens the scope of scalar-tensor models in large-scale physics

Abstract

We show that Renormalization Group extensions of the Einstein-Hilbert action for large scale physics are not, in general, a particular case of standard Scalar-Tensor (ST) gravity. We present a new class of ST actions, in which the potential is not necessarily fixed at the action level, and show that this extended ST theory formally contains the Renormalization Group case. We also propose here a Renormalization Group scale setting identification that is explicitly covariant and valid for arbitrary relativistic fluids.