Do f(R) theories matter?

TL;DR

This paper investigates a modified gravity theory with non-minimal coupling between curvature and matter, analyzing its effects on stellar equilibrium, Newtonian limits, and solar observables to constrain the model.

Contribution

It introduces and studies a modified f(R) gravity with non-minimal coupling, focusing on stellar and solar system implications and establishing observational constraints.

Findings

Constraints on non-minimal coupling from solar data

Modified gravity effects on stellar equilibrium

Analysis of boundary and exterior matching conditions

Abstract

We consider a modified action functional with a non-minimum coupling between the scalar curvature and the matter Lagrangian, and study its consequences on stellar equilibrium. Particular attention is paid to the validity of the Newtonian regime, and on the boundary and exterior matching conditions, as well as on the redefinition of the metric components. Comparison with solar observables is achieved through numerical analysis, and constraints on the non-minimum coupling are discussed.