Bianchi type I string cosmological models with bulk viscosity and magnetic field

Some locally rotationally symmetric (LRS) Bianchi type I cosmological models for a cloud string with bulk viscosity and magnetic field are presented. Where an equation of state rho=klambda and a relation between metric potential R=AS(n) are considered. The solution describes a shearing and nonrotating model with a big bang start. In the absence of magnetic field it reduces to a string model with bulk viscosity, where the relation between the coefficient of bulk viscosity and energy density is zeta proportional to rho(1/2). After choosing k=1+n/1-n, it further reduces to a string model without viscosity and magnetic field.