This paper proposes a physically plausible cosmological model in which a matter–dominated universe and an antimatter–dominated mirror universe originate simultaneously from a common zero–energy state, consistent with charge–parity–time (CPT) symmetry. Each universe evolves along its own arrow of time while strictly obeying the Second Law of Thermodynamics. As entropy monotonically increases within both domains, the universes asymptotically approach thermodynamic equivalence. The model demonstrates that complete convergence of the two entropic continua is not forbidden by any conservation law; therefore, a terminal overlap and subsequent vacuum–energy annihilation remain possible.
Byrne, Paul (Mon,) studied this question.