Model-independent parameterization of H(z) and its implications for cosmic evolution
Myrzakulov Y. Donmez O. Koussour M. Muminov S. Bekchanov S. Rayimbaev J.
August 2024Elsevier B.V.
Journal of High Energy Astrophysics
2024#43209 - 216 pp.
We investigate the model-independent parameterization of H(z) in spatially homogeneous and isotropic FLRW space-time using Cosmic Chronometers (31 data points) and Pantheon+SH0ES (1701 points) datasets. The best-fit values for the model parameters (H0,A1,A2,A3) are obtained through MCMC analysis. Our results show that the EoS parameter ω transitions from a matter-dominated era through quintessence to ω=−1, indicating convergence to ΛCDM at late times. The current ω values suggest an accelerating universe. Moreover, the models squared sound speed vs2 evolves from negative to positive, indicating increasing stability. The deceleration parameter q shows a smooth transition from deceleration to acceleration, with transition redshift zt between 0.5 and 0.8. Further, the energy conditions are satisfied, and SEC violation at z=0 supports current acceleration. The ω−ω′ plane lies in the freezing region, and the r−s plane approaches the ΛCDM limit at late times.
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Department of General & Theoretical Physics, L.N. Gumilyov Eurasian National University, Astana, 010008, Kazakhstan
Ratbay Myrzakulov Eurasian International Center for Theoretical Physics, Astana, 010009, Kazakhstan
College of Engineering and Technology, American University of the Middle East, Egaila, 54200, Kuwait
Department of Physics, University of Hassan II, Casablanca, Morocco
Department of Computer Science, Urgench State University, Kh. Alimjan str. 14, Urgench, 221100, Uzbekistan
Institute of Fundamental and Applied Research, National Research University, TIIAME, Kori Niyoziy 39, Tashkent, 100000, Uzbekistan
University of Tashkent for Applied Sciences, Str. Gavhar 1, Tashkent, 100149, Uzbekistan
Shahrisabz State Pedagogical Institute, Shahrisabz Str. 10, Shahrisabz, 181301, Uzbekistan
Tashkent State Technical University, Tashkent, 100095, Uzbekistan
Department of General & Theoretical Physics
Ratbay Myrzakulov Eurasian International Center for Theoretical Physics
College of Engineering and Technology
Department of Physics
Department of Computer Science
Institute of Fundamental and Applied Research
University of Tashkent for Applied Sciences
Shahrisabz State Pedagogical Institute
Tashkent State Technical University
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