Abstract :

In the present study, we have accounted for the accelerated expansion of the universe in the framework of the generalized Brans-Dicke theory. It has been shown very clearly that the transition of the universe from a phase of deceleration to that of acceleration can be explained by the generalized Brans-Dicke theory, without having to consider any contribution from the entity called dark energy. The present model shows a signature flip of the deceleration parameter, from a positive to a negative value,occurring in the recent past of the matter dominated era. We have determined the functional form of the Brans-Dicke parameter, expressed in terms of the scalar field. This functional form causes the effective pressure to be sufficiently negative to drive the accelerated expansion of the universe. It has been found in the present study that the gravitational constant increases with time.