Some Bianchi Type I Viscous Fluid Cosmological Models with a Variable Cosmological Constant

Abstract

Some Bianchi type I viscous fluid cosmological models with a variable cosmological constant are investigated in which the expansion is considered only in two direction i.e. one of the Hubble parameter $(H_1=\frac{A_4}{A})$ is zero. The viscosity coefficient of bulk viscous fluid is assumed to be a power function of mass density whereas the coefficient of shear viscosity is considered as constant in first case whereas in other case it is taken as proportional to scale of expansion in the model. The cosmological constant $\Lambda$ is found to be positive and is a decreasing function of time which is supported by results from recent supernovae Ia observations. Some physical and geometric properties of the models are also discussed.

16 pages

References in corpus (25)

• Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant
• Measurements of Omega and Lambda from 42 High-Redshift Supernovae
• The Cosmological Constant and Dark Energy
• Cosmological Constant - the Weight of the Vacuum
• The Case for a Positive Cosmological Lambda-term
• Discovery of a Supernova Explosion at Half the Age of the Universe and its Cosmological Implications
• Measurements of the Cosmological Parameters Omega and Lambda from the First 7 Supernovae at z >= 0.35
• The High-Z Supernova Search: Measuring Cosmic Deceleration and Global Cur vature of the Universe Using Type Ia Supernovae
• Supernova Limits on the Cosmic Equation of State
• Constraints on Cosmological Models from Hubble Space Telescope Observations of High-z Supernovae
• Bulk Viscous Cosmology
• Breaking Of Conformal Invariance And Electromagnetic Field Generation In The Universe
• Bulk Viscous Cosmology
• Consequences on variable Lambda-models from distant Type Ia supernovae and compact radio sources
• A study of the angular size-redshift relation for models in which $\Lambda$ decays as the energy density
• Higher spin fields and the problem of cosmological constant
• Bianchi Type I Magnetofluid Cosmological Models with Variable Cosmological Constant Revisited
• A Machian Model of Dark Energy
• Study of the Magnitude-Redshift Relation for type Ia Supernovae in a Model resulting from a Ricci-Symmetry
• Cosmological perturbations on a magnetised Bianchi I background
• Bianchi Type I Anisotropic Magnetized Cosmological Models with Varying $\Lambda$
• Consequences on some dark energy-candidates from the type Ia supernova SN 1997ff
• Plane-Symmetric Inhomogeneous Bulk Viscous Cosmological Models with Variable $\Lambda$
• Bulk Viscous Solutions to the Field Equations and the Deceleration Parameter-Revisited
• Some Inhomogeneous Magnetized Viscous Fluid Cosmological Models with Varying $\Lambda$

Cited by in corpus (15)

• Bianchi Type-I Anisotropic Dark Energy Models with Constant Deceleration Parameter
• Classical and Quantum Features of the Mixmaster Singularity
• Anisotropic Universe Models in Brans-Dicke Theory
• Bianchi Type-I Cosmological Models with Variable G and 4Λ$-Terms in General Relativity
• Bulk Viscous LRS Biachi-I Universe with variable $G$ and decaying $\Lambda$
• Phantom evolving wormholes with big rip singularities
• Magnetized Bianchi Type $V{I}_0$ Barotropic Massive String Universe with Decaying Vacuum Energy Density $\Lambda$
• Statefinder Parameters for Different Dark Energy Models with Variable G Correction in Kaluza-Klein Cosmology
• Variable cosmological term $\Lambda (t)$
• Effects of anisotropy on interacting ghost dark energy in Brans-Dicke theories
• Bianchi I with variable $G$ and $\Lambda$. Self-Similar approach
• About Bianchi I with VSL
• Skyrme Fluid in Anisotropic Universe
• Cosmological volume acceleration in dust epoch: using scaling solutions and variable cosmological term $\Lambda (t)$ within an anisotropic cosmological model
• The Dynamics of a Two-Fluid Bianchi Type I Universe