Acceleration and Deceleration in Curvature Induced Phantom Model of the Late and Future Universe, Cosmic Collapse as Well as Its Quantum Escape

Here, cosmology of the late and future universe is obtained from f(R)− gravity with non-linear curvature terms R and R (R being the Ricci scalar curvature). It is different from f(R)−dark energy models [6] where non-linear curvature terms are taken as gravitational alternative of dark energy. In the present model, neither linear nor non-linear curvature terms are taken as dark energy. Rather, dark energy terms are induced by curvature terms in the Friedmann equation derived from f(R)−gravitational equations. It has advantage over f(R)−dark energy models in the sense that the present model satisfies WMAP results and expands as ∼ t during matter dominance. So, it does not have problems due to which f(R)−dark energy models are criticised in [7]. Curvature-induced dark energy, obtained here, mimics phantom. Different phases of this model, including acceleration and deceleration during phantom phase, are investigated here. It is found 1