Observational constraints on a generalized equation of state model
Koussour M. Bekov S. Syzdykova A. Muminov S. Ibragimov I. Rayimbaev J.
February 2025Elsevier B.V.
Physics of the Dark Universe
2025#47
We investigate the cosmological implications of a generalized total equation of state (EoS) model by constraining its parameters using observational datasets to effectively characterize the universes expansion history and its dynamic properties. We introduce three parameters: α, β, and n to capture the EoS behavior across different evolutionary phases. Our analysis indicates that at high redshifts (z≫1), the EoS approaches a matter- or radiation-dominated regime, transitioning to a dark energy-dominated phase as z→−1, where it tends toward a constant value α. Using a Markov Chain Monte Carlo (MCMC) method, we analyze a combined dataset that includes 31 data points from H(z) and 1701 data points from the Pantheon+ dataset. The results reveal a smooth transition from deceleration to acceleration in the universes expansion, with current EoS values suggesting quintessence-like behavior. The model aligns with observations and indicates that dark energy is dynamically evolving rather than acting as a cosmological constant. Furthermore, energy conditions and stability analyses highlight the nature and future of dark energy. This parametrized EoS model thus offers a robust framework for understanding the complexities of dark energy and the evolution of the cosmos.
And energy conditions , Cosmological models , Dark energy , Equation of state , MCMC , Quintessence
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Department of Physics, University of Hassan II Casablanca, Morocco
Department of General and Theoretical Physics, L.N. Gumilyov Eurasian National University, Astana, 010008, Kazakhstan
Kozybayev University, Petropavlovsk, 150000, Kazakhstan
Mamun University, Bolkhovuz Street 2, Khiva, 220900, Uzbekistan
Kimyo International University in Tashkent, Shota Rustaveli street 156, Tashkent, 100121, 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
Urgench State University, Kh. Alimjan Str. 14, Urgench, 221100, Uzbekistan
Shahrisabz State Pedagogical Institute, Shahrisabz Str. 10, Shahrisabz, 181301, Uzbekistan
Department of Physics
Department of General and Theoretical Physics
Kozybayev University
Mamun University
Kimyo International University in Tashkent
Institute of Fundamental and Applied Research
University of Tashkent for Applied Sciences
Urgench State University
Shahrisabz State Pedagogical Institute
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