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arXiv · 2102.06951

Energy conditions for a $(WRS)_4$ spacetime in $F(R)$-gravity

Avik De·Tee-How Loo·Simran Arora·P. K. Sahoo
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Abstract

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, $F(R)=e^{\alpha R}$ where $\alpha$ is constant and $F(R)=R-\beta \tanh(R)$, $\beta$ is a constant. We also find that the equation of state parameter (EoS) in both models supports the universe's accelerating behavior, i.e., $\omega=-1$. 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.

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Avik De, Tee-How Loo, Simran Arora, P. K. Sahoo. 2021-02-13. Energy conditions for a $(WRS)_4$ spacetime in $F(R)$-gravity. https://doi.org/10.1140/epjp/s13360-021-01216-2

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