Constrained evolution of effective equation of state parameter in non-linear f(R,Lm) dark energy model: insights from Bayesian analysis of cosmic chronometers and Pantheon samples
Myrzakulov N. Koussour M. Alfedeel A.H.A. Abebe A.
September 2023Springer Science and Business Media Deutschland GmbH
European Physical Journal Plus
2023#138Issue 9
We conduct a Bayesian analysis of recent observational datasets, specifically the Cosmic Chronometers (CC) dataset and Pantheon samples, to investigate the evolution of the EoS parameter in dark energy models. Our study focused on the effective EoS parameter, which is described by the parametric form ωeff=-11+m(1+z)n , where m and n are model parameters. This parametric form is applicable within the framework of f(R, Lm) gravity, where R represents the Ricci scalar and Lm is the matter Lagrangian. Here, we examine a non-linear f(R, Lm) model characterized by the functional form f(R,Lm)=R2+Lmα , where α is the free parameter of the model. We examine the evolution of several cosmological parameters, including the effective EoS parameter ωeff , the deceleration parameter q, the density parameter ρ , the pressure p, and the statefinder parameters. Our analysis revealed that the constrained current value of the effective EoS parameter, ωeff0=-0.68±0.06 for both the CC and Pantheon datasets, points towards a quintessence phase. Moreover, at redshift z= 0 , the deceleration parameter, q0=-0.61-0.01+0.01 , indicates that the present Universe is undergoing accelerated expansion.
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L. N. Gumilyov Eurasian National University, Astana, 010008, Kazakhstan
Ratbay Myrzakulov Eurasian International Centre for Theoretical Physics, Astana, 010009, Kazakhstan
Quantum Physics and Magnetism Team, LPMC, Faculty of Science Ben M’sik, Casablanca Hassan II University, Casablanca, Morocco
Department of Mathematics and Statistics, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh, 13318, Saudi Arabia
Department of Physics, Faculty of Science, University of Khartoum, Khartoum, P.O. Box 321, 11115, Sudan
Centre for Space Research, North-West University, Potchefstroom, 2520, South Africa
National Institute for Theoretical and Computational Sciences (NITheCS), Stellenbosch, 3201, South Africa
L. N. Gumilyov Eurasian National University
Ratbay Myrzakulov Eurasian International Centre for Theoretical Physics
Quantum Physics and Magnetism Team
Department of Mathematics and Statistics
Department of Physics
Centre for Space Research
National Institute for Theoretical and Computational Sciences (NITheCS)
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