The objective of the present paper is to study 4-dimensional weakly Ricci symmetric spacetimes (WRS)4 with non-zero constant Ricci scalar. We prove that such a (WRS)4 satisfying F(R)-gravity field equations represents a perfect fluid with vanishing vorticity. Some energy conditions are studied under the current setting to constrain the functional form of F(R). We examine a couple of popular toy models in F(R)-gravity, F(R)=eαR where α is constant and F(R)=R−βtanh(R), β is a constant. We also find that the equation of state parameter (EoS) in both models supports the universe's accelerating behavior, i.e., ω=−1. According to the recently suggested observations of accelerated expansion, both cases define that the null, weak, and dominant energy conditions justify their requirements while the strong energy conditions violate them.
@article{arxiv.2102.06951,
title = {Energy conditions for a $(WRS)_4$ spacetime in $F(R)$-gravity},
author = {Avik De and Tee-How Loo and Simran Arora and P. K. Sahoo},
journal= {arXiv preprint arXiv:2102.06951},
year = {2021}
}