Physical aspects of ${f}(R,G_{\mu \nu}T^{\mu \nu})$ modified gravity theories
Abstract
The paper extends basic EinsteinHilbert action by adding a newly proposed invariant constructed from a specific contraction between the Einstein tensor and the energy momentum tensor, encoding a nonminimal coupling between the spacetime geometry and the matter fields. The fundamental EinsteinHilbert action is extended by considering a generic function ${f}(R,G_{\mu \nu}T^{\mu \nu})$ which is further decomposed into its main constituents, a geometric component which depends on the scalar curvature, and a second element embedding the interplay between geometry and matter fields. Specific cosmological models are established at the level of background dynamics, based on particular couplings between the matter energymomentum tensor and the Einstein tensor. After deducing the resulting field equations, the physical aspects for the cosmological model are investigated by employing a dynamical system analysis for various coupling functions. The investigation showed that the present model is compatible with different epochs in the evolution of our Universe, possible explaining various late time historical stages.
 Publication:

arXiv eprints
 Pub Date:
 February 2023
 DOI:
 10.48550/arXiv.2302.04186
 arXiv:
 arXiv:2302.04186
 Bibcode:
 2023arXiv230204186M
 Keywords:

 General Relativity and Quantum Cosmology;
 High Energy Physics  Theory;
 Physics  Computational Physics