Oscillating Rastall-Gravity Cyclic Universe Crossing the Phantom Divide
A cyclic, spatially flat cosmological model built in Rastall gravity in which a periodically oscillating deceleration parameter drives a Hubble parameter that alternates sign from one cycle to the next, producing quintom behaviour that crosses the phantom-divide line (w = -1) and terminates in a future Big Rip at roughly 8.7 Gyr. The model preserves causality except near the initial and Big-Rip singularities and is tested against apparent-horizon thermodynamics, entropy, and the standard energy conditions.
Oscillating Rastall-Gravity Cyclic Universe Crossing the Phantom Divide
A cyclic flat universe with quintom behaviour and future big rip has been presented in the framework of Rastall gravity, which is an extension of the standard $Λ$CDM model. The Hubble parameter oscil…