Testing a non-minimal coupling between matter and curvature

TL;DR

This paper explores a non-minimal matter-curvature coupling in extended gravity theories, analyzing its implications for astrophysics and cosmology, including dark matter, dark energy, and early universe phenomena.

Contribution

It provides a unified analysis of non-minimal matter-curvature coupling effects across astrophysical and cosmological contexts, highlighting its potential to explain dark matter and dark energy.

Findings

Non-minimal coupling can mimic galactic dark matter effects.

It offers a mechanism for cosmic acceleration without dark energy.

The model is equivalent to multi-scalar theories.

Abstract

One of the most interesting and current phenomenological extensions of General Relativity is the so-called $f (R)$ class of theories; a natural generalization of this includes an explicit non-minimal coupling between matter and curvature. The purpose of this work is to present a unified view of the applicability of the latter to various contexts, ranging from astrophysical matter distributions to a cosmological setting. Various results are discussed, including the impact of this non-minimal coupling in the choice of Lagrangian density, a mechanism to mimic galactic dark matter and a Cosmological Constant at a astrophysical scale, the possibility of accounting for the accelerated expansion of the Universe and modifications to post-inflationary reheating. The equivalence between a model exhibiting a non-minimal coupling and multi-scalar-theories is also discussed.