Isotropic Exact Solutions via Noether Symmetries in $f(R,T,R_{\mu\nu}T^{\mu\nu})$ Gravity

Iqra Nawazish; M. Sharif

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arXiv · 2401.06812

Isotropic Exact Solutions via Noether Symmetries in $f(R,T,R_{\mu\nu}T^{\mu\nu})$ Gravity

Iqra Nawazish·M. Sharif

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Abstract

In this paper, we study cosmic evolutionary stages in the background of modified theory admitting non-minimal coupling between Ricci scalar, trace of the energy-momentum tensor, contracted Ricci and energy-momentum tensors. For dust distribution, we consider isotropic, homogeneous and flat cosmic model to determine symmetry generators, conserved integrals and exact solutions using Noether symmetry scheme. We find maximum symmetries for non-minimally interacting Ricci scalar and trace of the energy-momentum tensor but none of them correspond to any standard symmetry. For rest of the models, we obtain scaling symmetry with conserved linear momentum. The graphical analysis of standard cosmological parameters, squared speed of sound, viability conditions suggested by Dolgov-Kawasaki instability and state-finder parameters identify realistic nature of new models compatible with Chaplygin gas model, quintessence and phantom regions. The fractional densities relative to ordinary matter and dark energy are found to be consistent with Planck 2018 observational data. It is concluded that the constructed non-minimally coupled models successfully explore cosmic accelerated expansion.

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Iqra Nawazish, M. Sharif. 2024-01-11. Isotropic Exact Solutions via Noether Symmetries in $f(R,T,R_{\mu\nu}T^{\mu\nu})$ Gravity. https://arxiv.org/abs/2401.06812

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