We have studied five-dimensional homogeneous cosmological models with variableG and bulk viscosity in Lyra geometry. Exact solutions for the field equations have been obtained and physical properties of the models are discussed. It has been observed that the results of new models are well within the observational limit.

We have studied the evolution of a homogeneous, anisotropic universe given by a Bianchi Type-V cosmological model filled with viscous fluid, in the presence of cosmological constant 𝛬. The role of viscous fluid and 𝛬-term in the Bianchi Type-V universe has been studied.

In modified generalized scalar–tensor (GST) theory, the cosmological term 𝛬 is a function of the scalar field 𝜙 and its derivatives $\dot{\phi}^{2}$. We obtain exact solutions of the field equations in Bianchi Type-I, V and VIo space–times. The evolution of the scale factor, the scalar field and the cosmological term has been discussed. The Bianchi Type-I model has been discussed in detail. Further, Bianchi Type-V and VIo models can be studied on the lines similar to Bianchi Type-I model.

The Bianchi Type-I Universe filled with dark energy from a wet dark fluid has been considered. A new equation of state for the dark energy component of the Universe has been used. It is modeled on the equation of state $p = \gamma(\rho − \rho_{*})$ which can describe a liquid, for example water. The exact solutions to the corresponding field equations are obtained in quadrature form. The solution for constant deceleration parameter have been studied in detail for both power-law and exponential forms. The cases $\gamma = 1$ and $\gamma = 0$ have also been analysed.