Dissipative Unified Dark Fluid Model

Abstract

We consider a unified dissipative dark fluid model. Our fluid contains an adiabatic part plus a bulk viscous one. The adiabatic part has the ability to asymptote between two power laws and so can interpolate between the dust and dark energy equations of state at early and late times. The dissipative part is a bulk viscous part with constant viscosity coefficient. The model is analyzed using the phase space methodology which helps to understand the dynamical behavior of the model in a robust manner without reference to the system solution. The parameters of the model are constrained through its asymptotic behavior and also through many observational constraints. We solve the Hubble parameter equation using numerical methods and results are plotted against the newest set of Hubble data. The model is tested using the $Om(z)$ test which shows that this model although is a quintessence-like model, it slides through the phantom barrier. We study the model expectations for the evolution of the universe by studying the evolution of the deceleration parameter, the density of the universe, the effective equation of state parameter of the model and of its underlying dark energy package. We estimate the value of the present day viscosity coefficient of the cosmic fluid as $8\times 10^{6}Pa.s$, which agrees with the work of many authors, e.g., Velten and Schwartz [26], Wang and Meng [27], and Sasidharan and Mathew [29]. We argue that this model is able to explain the behavior of the universe evolution.

References in corpus (14)

• Dynamics of dark energy
• The Complete Light-curve Sample of Spectroscopically Confirmed Type Ia Supernovae from Pan-STARRS1 and Cosmological Constraints from The Combined Pantheon Sample
• Two new diagnostics of dark energy
• Hubble parameter measurement constraints on the redshift of the deceleration-acceleration transition, dynamical dark energy, and space curvature
• Viscous Cosmology for Early- and Late-Time Universe
• The clustering of the SDSS-IV extended Baryon Oscillation Spectroscopic Survey DR14 quasar sample: a tomographic measurement of cosmic structure growth and expansion rate based on optimal redshift weights
• Does Bulk Viscosity Create a Viable Unified Dark Matter Model?
• Measuring Dark Energy Properties with Photometrically Classified Pan-STARRS Supernovae. II. Cosmological Parameters
• Exploring a matter-dominated model with bulk viscosity to drive the accelerated expansion of the Universe
• Dissipation of dark matter
• Non-adiabatic dark fluid cosmology
• Phase Portraits of general f(T) Cosmology
• Introduction to the application of the dynamical systems theory in the study of the dynamics of cosmological models of dark energy
• Inflationary generalized Chaplygin gas and dark energy in the light of the Planck and BICEP2 experiments

Cited by in corpus (7)

• A preference for dynamical phantom dark energy using one-parameter model with Planck, DESI DR1 BAO and SN data
• A PAge-like Unified Dark Fluid Model
• Holographic representation of the unified early and late universe via a viscous dark fluid
• Unified dark fluid with null sound speed as an alternative to phantom dark energy
• Holographic description of unified early and late universe in viscous mimetic gravity
• Holographic description of the dissipative unified dark fluid model with axion field
• Physical Implications and Updated Observational Constraints of the PAge-like Unified Dark Fluid Model