English

Reconstruction of the singularity-free $f(\mathcal{R})$ gravity via Raychaudhuri equations

General Relativity and Quantum Cosmology 2024-07-30 v3 High Energy Physics - Theory

Abstract

We study the bounce cosmology to construct a singularity-free f(R)f(\mathcal{R}) model using the reconstruction technique. The formulation of the f(R)f(\mathcal{R}) model is based on the Raychaudhari equation, a key element employed in reconstructed models to eliminate singularities. We explore the feasibility of obtaining stable gravitational Lagrangians, adhering to the conditions fR>0f_{\mathcal{R}}>0 and fRR>0f_{\mathcal{R}\mathcal{R}}>0. Consequently, both models demonstrate stability, effectively avoiding the Dolgov-Kawasaki instability. Our assessment extends to testing the reconstructed model using energy conditions and the effective equation-of-state (EoS). Our findings indicate that the reconstructed super-bounce model facilitates the examination of a singularity-free accelerating universe for both phantom and non-phantom phases. However, in the case of the reconstructed oscillatory bounce model, two scenarios are considered with ω=1/3\omega=-1/3 and ω=2/3\omega=-2/3. While the model proves suitable for studying a singular-free accelerating universe in the ω=1/3\omega=-1/3 case, it fails to demonstrate such behavior under energy conditions for the ω=2/3\omega=-2/3 scenario. The reconstructed models accommodate early-time bouncing behavior and late-

Keywords

Cite

@article{arxiv.2402.04813,
  title  = {Reconstruction of the singularity-free $f(\mathcal{R})$ gravity via Raychaudhuri equations},
  author = {Gaurav N. Gadbail and Simran Arora and P. K. Sahoo and Kazuharu Bamba},
  journal= {arXiv preprint arXiv:2402.04813},
  year   = {2024}
}

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EPJC published version