Scalar perturbation of the viscosity dark fluid cosmological model

Abstract

A general equation of state is used to model unified dark matter and dark energy (dark fluid), and it has been proved that this model is equivalent to a single fluid with time-dependent bulk viscosity. In this paper, we investigate scalar perturbation of this viscosity dark fluid model. For particular parameter selection, we find that perturbation quantity can be obtained exactly in the future universe. We numerically solve the perturbation evolution equations, and compare the results with those of $\Lambda$CDM model. Gravitational potential and the density perturbation of the model studied here have the similar behavior with the standard model, though there exists significant value differences in the late universe.

11 pages, 7 figures

References in corpus (15)

• Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Dark Energy and the Accelerating Universe
• Properties of singularities in (phantom) dark energy universe
• Improved Dark Energy Constraints from ~100 New CfA Supernova Type Ia Light Curves
• Inhomogeneous Equation of State of the Universe: Phantom Era, Future Singularity and Crossing the Phantom Barrier
• Observational constraints on dark energy with generalized equations of state
• Approaches to Understanding Cosmic Acceleration
• Does Bulk Viscosity Create a Viable Unified Dark Matter Model?
• Cosmological model with viscosity media (dark fluid) described by an effective equation of state
• Friedmann cosmology with bulk viscosity: a concrete model for dark energy
• $\Lambda \alpha$DM: Observational constraints on unified dark matter with constant speed of sound
• Non-adiabatic dark fluid cosmology
• Constraining the dark fluid
• Affine parameterization of the dark sector: costraints from WMAP5 and SDSS
• Viscous dark fluid