Spherically Symmetric, Static Solutions in Presence of Matter-Curvature Coupling

TL;DR

This paper explores spherically symmetric, static solutions in a gravity theory with non-minimal coupling between spacetime curvature and matter, revealing new metric solutions and complex stress-energy tensor behaviors.

Contribution

It introduces new classes of solutions in non-minimally coupled gravity theories and analyzes their effects on the stress-energy tensor and energy conditions.

Findings

Existence of new metric solutions due to NMC.

NMC affects the nature of the source fluid.

Complexity in stress-energy tensor definitions and energy conditions.

Abstract

In this work we have proposed some spherically symmetric, static spacetimes in a theory of gravity which permits non-minimal coupling (NMC) between curvature of spacetime and fluid variables. It is shown that these non-minimally coupled theories may admit of new class of metric solutions. Known metric solutions from GR can also be solutions of the non-minimally coupled theories, for these cases the NMC affects the nature of the fluid which sources the spacetime. The paper presents multiple ways in which the modified field equations appearing in non-minimally coupled theories can be solved. The NMC produces multiple definitions of the stress-energy tensor. The paper discusses the complexity related to these sources of curvature as, unlike in minimally coupled general relativity, in the present theory the Ricci curvature itself can affect the stress-energy tensor of the effective fluid which seeds spacetime curvature. The various energy conditions related to various forms of possible stress-energy tensors are presented in the paper.