Bianchi type-III bulk-viscous string models in scalar–tensor theory of gravitation

Abstract

In this paper, we have investigated Bianchi type-III bulk-viscous string cosmological models in the frame-work of scalar–tensor theory of gravitation. To solve the field equations for the bulk-viscous fluid and perfect fluid under the following physically relevant conditions: (i) Expansion scalar ([Formula: see text]) in the model is directly proportional to the shear scalar ([Formula: see text]). (ii) [Formula: see text], where [Formula: see text] is a constant (iii) [Formula: see text], where [Formula: see text] and [Formula: see text] are real constants. The observed phase transition of the presented universe from the early decelerating phase to the present epoch is in good accordance with the astronomical measurements. A detailed discussion on energy conditions and stability of the all models is analyzed through graphical representation.