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Kantowski-sachs string cosmological model with bulk viscosity in general relativity. (English) Zbl 1081.83550
Summary: String cosmological models with bulk viscosity are investigated in Kantowski-Sachs space-time. To obtain a determinate solution, it is assumed that the coefficient of bulk viscosity is a power function of the scalar of expansion $\xi = k\theta^{m}$ and the scalar of expansion is proportional to the shear scalar $\theta \propto \sigma$, which leads to a relation between metric potentials $R = AS^{n}$. The physical and geometrical aspects of the model are also discussed. It is shown that the bulk viscosity has significant influence on the evolution of the universe. There is a `big bang’ start in the model when $m \leq 1$ but there is no `big bang’ start when $m > 1$.

83F05Relativistic cosmology
Full Text: DOI
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