Abstract
Inspired by thermodynamical dissipative phenomena, we consider bulk viscosity for dark fluid in a spatially flat two-component Universe. Our viscous dark energy model represents phantom-crossing which avoids big-rip singularity. We propose a non-minimal derivative coupling scalar field with zero potential leading to accelerated expansion of the Universe in the framework of bulk viscous dark energy model. In this approach, the coupling constant, kappa , is related to viscosity coefficient, gamma , and the present dark energy density, varOmega _mathrm{DE}^0. This coupling is bounded as kappa in [-1/9H_0^2(1-varOmega _mathrm{DE}^0), 0]. We implement recent observational data sets including a joint light-curve analysis (JLA) for SNIa, gamma ray bursts (GRBs) for most luminous astrophysical objects at high redshifts, baryon acoustic oscillations (BAO) from different surveys, Hubble parameter from HST project, Planck CMB power spectrum and lensing to constrain model free parameters. The joint analysis of JLA + GRBs + BAO + HST shows that varOmega _mathrm{DE}^0=0.696pm 0.010, gamma =0.1404pm 0.0014 and H_0=68.1pm 1.3. Planck TT observation provides gamma =0.32^{+0.31}_{-0.26} in the 68% confidence limit for the viscosity coefficient. The cosmographic distance ratio indicates that current observed data prefer to increase bulk viscosity. The competition between phantom and quintessence behavior of the viscous dark energy model can accommodate cosmological old objects reported as a sign of age crisis in the varLambda CDM model. Finally, tension in the Hubble parameter is alleviated in this model.
Highlights
The accelerating expansion of the Universe has been confirmed by many observational data sets [1,2]
To make more obvious concerning the knowledge of bulk viscosity, we will rely on modified general relativity to obtain corresponding scalar field giving rise to accelerated expansion of Universe in the context of bulk viscous dark energy scenario
We demonstrate that at the late time, there is a significant variation in the behavior of the viscous dark energy model, in order to distinguish between cosmological constant and our model we should take into account those indicators which are more sensitive around late time
Summary
The accelerating expansion of the Universe has been confirmed by many observational data sets [1,2]. To make more obvious concerning the knowledge of bulk viscosity, we will rely on modified general relativity to obtain corresponding scalar field giving rise to accelerated expansion of Universe in the context of bulk viscous dark energy scenario. With this mechanism, we will show the correspondence between our viscous dark energy model and the scalar–tensor theories in a two-component dark sectors model in contrast to that of done in [29,30]. We use Lagrangian approach with a non-minimal derivative coupling scalar field in order to provide a theoretical model for clarifying the correspondence of the viscous dark energy, in Sect.
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