Abstract:
This thesis explain the possibility of obtaining repulsive gravity. Because of the decelerating particles (i.e., Mediators) lead to attractive of gravity in the early universe. Therefore, one can explain the repulsive gravity arising from increasing the rate of accelerating of these particles at certain time in the future. However, we assume this is similar to particles connected by compressed spring beside stretched one or nucleus surrounding by electronic cloud. Moreover, the particles propagating in a negative curvature space (in Robertson –Walker background) are effectively accelerated, which it mimics the repulsive nature of gravity.
