Friedmann cosmology with a generalized equation of state and bulk viscosity

Abstract

The universe media is considered as a non-perfect fluid with bulk viscosity and described by a more general equation of state. We assume the bulk viscosity is a linear combination of the two terms: one is constant, and the other is proportional to the scalar expansion $\theta =3\dot{a}/a$. The equation of state is described as $p=(\gamma -1)\rho +p_0$, where $p_0$ is a parameter. This model can be used to explain the dark energy dominated universe. Different choices of the parameters may lead to three kinds of fates of the cosmological evolution: no future singularity, big rip, or Type III singularity of Ref. [S. Nojiri, S.D. Odintsov, and S. Tsujikawa, Phys. Rev. D \textbf{71}, 063004 (2005)].

5 pages and 4 figs

References in corpus (33)

• Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant
• Discovery of a Supernova Explosion at Half the Age of the Universe and its Cosmological Implications
• Phantom Energy and Cosmic Doomsday
• Modified gravity with negative and positive powers of the curvature: unification of the inflation and of the cosmic acceleration
• Properties of singularities in (phantom) dark energy universe
• The Cosmic Triangle: Revealing the State of the Universe
• Late-time cosmology in (phantom) scalar-tensor theory: dark energy and the cosmic speed-up
• The State of the Dark Energy Equation of State
• Where new gravitational physics comes from: M-theory?
• 1/R Curvature Corrections as the Source of the Cosmological Acceleration
• Quantum escape of sudden future singularity
• Probing dark energy perturbations: the dark energy equation of state and speed of sound as measured by WMAP
• Bulk Viscous Cosmology
• Cosmic anti-friction and accelerated expansion
• Higher order gravity theories and scalar tensor theories
• Cosmological model with viscosity media (dark fluid) described by an effective equation of state
• Dark energy cosmology with generalized linear equation of state
• Viscous dark energy and phantom evolution
• Cosmological Evolution in 1/R-Gravity Theory
• Bulk viscous cosmology: statefinder and entropy
• Effects of the Sound Speed of Quintessence on the Microwave Background and Large Scale Structure
• Modified Friedmann Equations in R${}^{-1}$-Modified Gravity
• Palatini Formulation of Modified Gravity with $\ln R$ Terms
• Cosmological particle production, causal thermodynamics, and inflationary expansion
• Constraints on the sound speed of dark energy
• Cosmological solutions with nonlinear bulk viscosity
• Gravitational potential in Palatini formulation of modified gravity
• Qualitative Viscous Cosmology
• $R^2$ corrections to the cosmological dynamics of inflation in the Palatini formulation
• Palatini formulation of the $R^{-1}$modified gravity with an additionally squared scalar curvature term
• Cardy-Verlinde Entropy Formula in the Presence of a General Cosmological State Equation
• Evolution of the Luminosity Density in the Universe: Implications for the Nonzero Cosmological Constant
• Qualitative analysis of dissipative cosmologies

Cited by in corpus (36)

• Dark Energy
• Friedmann model with viscous cosmology in modified $f(R,T)$ gravity theory
• Viscous Ricci Dark Energy
• Friedmann cosmology with bulk viscosity: a concrete model for dark energy
• Viscous dark energy and generalized second law of thermodynamics
• Quintessence Behaviour of an Anisotropic Bulk Viscous Cosmological Model in Modified $f(Q)$-Gravity
• Latest Observational Constraints to the Ghost Dark Energy Model by Using Markov Chain Monte Carlo Approach
• Bulk viscous cosmology: unified dark matter
• Polytropic dark matter flows illuminate dark energy and accelerated expansion
• Bulk viscous cosmological model in $f(R,T)$ theory of gravity
• Constraining viscous dark energy models with the latest cosmological data
• Interacting viscous ghost tachyon, K-essence and dilaton scalar field models of dark energy
• Interacting Two-Fluid Viscous Dark Energy Models In Non-Flat Universe
• Two-Fluid Dark Energy Models in Bianchi Type-III Universe with Variable Deceleration Parameter
• Dark Energy: The Shadowy Reflection of Dark Matter?
• Cardassian Universe Constrained by Latest Observations
• Viscous cosmology in $f(T)$ gravity
• Probing bulk viscous matter-dominated models with Gamma-ray bursts
• Cosmological test on viscous bulk models using Hubble Parameter measurements and type Ia Supernovae data
• Rip/singularity free cosmology models with bulk viscosity
• A new pressure-parametrization unified dark fluid model
• No evidence for dynamical dark energy in two models
• Viscous universe with cosmological constant
• Stability of viscous fluid in Bianchi type-VI model with cosmological constant
• First comprehensive constraints on the Finslerian models using cosmological observations
• Hamiltonian formalism in Friedmann cosmology and its quantization
• Global 21-cm brightness temperature in viscous dark energy models
• Bulk viscous matter in $f(T)$ gravity: A path to cosmic acceleration
• Brane Kantowski-Sachs Universe with Linear Equation of State and Future Singularity
• Viscous fluid dynamics with decaying vacuum energy density
• Wormholes in a viscous universe
• Ricci cosmology in light of astronomical data
• Quintessence dark energy model in non-linear $f(Q)$ theory with bulk-viscosity
• Note on bulk viscosity as an alternative to dark energy
• Late time cosmological solutions in $f(R,T)$ gravity in a viscous Universe
• Matter loops corrected modified gravity in Palatini formulation