Constraints on bulk viscosity in f(Q, T) gravity from H(z)/Pantheon+ data

作     者：Koussour, M. Errehymy, Abdelghani Donmez, O. Myrzakulov, K. Khan, M.A. Çil, B. Güdekli, E. 

作者机构：Department of Physics University of Hassan II Casablanca Morocco Astrophysics Research Centre School of Mathematics Statistics and Computer Science University of KwaZulu-Natal Private Bag X54001 Durban4000 South Africa College of Engineering and Technology American University of the Middle East Egaila54200 Kuwait Department of General and Theoretical Physics L.N. Gumilyov Eurasian National University Astana010008 Kazakhstan  P.O. Box 65892 Riyadh11566 Saudi Arabia Graduate School of Engineering and Science Istanbul University Istanbul34134 Turkey Faculty of Sciences and Literature Department of Mathematics Haliç University Istanbul34060 Turkey Department of Physics Istanbul University Istanbul34134 Turkey 

出 版 物：《arXiv》 (arXiv)

年 卷 期：2024年

核心收录：

主　　题：Gravitation 

摘      要：In this study, we investigate the role of bulk viscosity in f(Q, T) gravity in explaining late-time cosmic acceleration. This model, an extension of symmetric teleparallel gravity, introduces viscosity into cosmic matter dynamics for a more realistic representation. Specifically, we consider the linear form of f(Q, T) = αQ+ βT, where α and β are free model parameters. To assess the model, we derive its exact solution and use Hubble parameter H(z) data and Pantheon + SNe Ia data for parameter estimation. We employ the χ2 minimization technique alongside the MCMC random sampling method to determine the best-fit parameters. Then, we analyze the behavior of key cosmological parameters, including the deceleration parameter, bulk viscous matter-dominated universe density, effective pressure, and the effective EoS parameter, accounting for the viscous type fluid. We observe a transition in the deceleration parameter from a positive (decelerating) to a negative (accelerating) phase at transition redshift zt. The matter density shows the expected positive behavior, while the pressure, influenced by viscosity, exhibits negative behavior, indicative of accelerating expansion. Furthermore, we investigate the energy conditions and find that while the NEC and DEC meet positivity criteria, the SEC is violated in the present and future epochs. The Om(z) diagnostic suggests that our model aligns with quintessence behavior. Finally, our f(Q, T) cosmological model, incorporating bulk viscosity effects, provides a compelling explanation for late-time cosmic behavior, consistent with observational data. Copyright © 2024, The Authors. All rights reserved.