Cosmological constraints on bulk viscous f(Q,T) gravity

Abstract In the General Theory of Relativity (GR) gravitational interactions are described by the scalar Ricci curvature. But there exists another class of modified gravity theories equivalent to GR, described by the torsion tensor or non‐metricity scalar. One of such theories, investigated in this paper is gravity, built from the arbitrary function of non‐metricity scalar non‐minimally coupled to the trace of stress‐energy tensor. Current work is aimed on the linear gravity, where and are free MOG parameters to be varied. As well, we assume that the fluid is bulk‐viscous with pressure and the bulk viscosity parameter . From the modified Einstein Field Equations (EFE's) we obtain the Hubble parameter analytically and constrain free parameters of the model through the MCMC sampling of 57 recent Hubble parameter observations. We found that computed Hubble rate for our model from MCMC sampling converges with the observational data at the confidence level. To examine the current accelerated expansion rate of the universe in details we use the statefinder diagnostics. Besides, to distinguish CDM and our model we use analysis.

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