Theoretical physics

Mathematical physics

Volume viscosity

Equation of state

Scalar field

Classical mechanics

Viscous liquid

Thermodynamics

Physics

Homogeneous

Scalar (mathematics)

Mathematics

Energy density

Mathematical analysis

Differential geometry

Geometry

Viscosity

Mechanics

Barotropic fluid

Perfect fluid

arXiv (Cornell University)

A spatially homogeneous and locally rotationally symmetric Bianchi type-II cosmological model under the influence of both shear and bulk viscosity has been studied. Exact solutions are obtained with a barotropic equation of state between thermodynamics pressure and the energy density of the fluid, and considering the linear relationships amongst the energy density, the expansion scalar and the shear scalar. Special cases with vanishing bulk viscosity coefficients and with the perfect fluid in the absence of viscosity have also been studied. The formal appearance of the solutions is the same for both the viscous as well as the perfect fluids. The difference is only in choosing a constant parameter which appears in the solutions. In the cases of either a fluid with bulk viscosity alone or a perfect fluid, the barotropic equation of state is no longer an additional assumption to be imposed; rather it follows directly from the field equations.

Bianchi Type-II Cosmological Model with Viscous Fluid