SOME BULK VISCOUS MAGNETIZED LRS BIANCHI TYPE-I STRING COSMOLOGICAL MODELS IN LYRA'S GEOMETRY

Some anisotropic locally rotationally symmetric (LRS) bulk viscous magnetized Bianchi type-I string cosmological models are studied in context of Lyra's geometry. The modified Einstein's field equations have been solved by taking a physically valuable condition that shear scalar (sigma) is proportional to the scalar expansion (theta) which leads to A = aB(n). This general solution in terms of metric potential (B) describe the characteristic of string Universe in presence of bulk viscosity and magnetic field. The study reveals that the coefficient of viscosity decreases uniformly with cosmic expansion during evolution of universe. In absence of magnetic field, the model can exit during the a span of time and the energy conditions can be fulfilled for a finite interval of time due to presence of bulk viscosity. It has been found that the displacement vector (beta) is a decreasing function of time and it approaches to small positive value at late time, which is collaborated with Halford (Aust. J. Phys. 23, 863, 1970) as well as recent observations of SN Ia. The physical behavior of derived models are also described.