An extension of the Friedman open cosmological model in the presence of viscosity

The problem of generalization of the previously obtained open cosmological model when accounting for radiation, and bulk viscosity is considered. The method that reduces the open Universe simulation to a problem of mechanical motion of the particle in a given force field is used. Cosmological model is described by the conformally-flat metric. New exact cosmological solution of the simple type gravitational equations is found. This solution corresponds to the equivalent oscillator with variable frequency and damping factor. Function of state is introduced as generalization of the previously considered case. For the asymptotic behavior of cosmological model close to the Friedman asymptotic, the pressure satisfies only for the ultrarelativistic equation of state.