String Cosmological Model in 5-Dimensional Space-Time: Interacting with iscous Fluid

Considering bulk viscosity as (i) constant quantity and (ii) functions of cosmic time, the field equations in 5-dimensional Bianchi type-I model in the context of general theory of relativity, has been obtained and solved in this paper by the use of certain physical assumptions, which are agreeing with the present observational findings. In both cases, the model represents an exponentially expanding and accelerating Universe that starts with volume 0 and stops with infinite volume. The model has an initial singularity and will eventually approach the de-Sitter phase ( ). It also satisfies the energy conditions  and . This model represents a matter-dominated Universe that agrees with current observational data. The model is anisotropic one and shearing throughout its evolution for .Considering bulk viscosity as (i) constant quantity and (ii) functions of cosmic time, the field equations in 5-dimensional Bianchi type-I model in the context of general theory of relativity, has been obtained and solved in this paper by the use of certain physical assumptions,which are agreeing with the present observational findings. In both cases, the model represents an exponentially expanding and accelerating Universe that starts with volume 0 and stops with infinite volume. The model has an initial singularity and will eventually approach the de-Sitter phase ( ). It also satisfies the energy conditions  and . This model represents a matter-dominated Universe that agrees with current observational data. The model is anisotropic one and shearing throughout its evolution for .