Theoretical necessity of the Accelerating Universe

We obtain that Universe space has to be flat, but also, at the same time, it has to be finite, homogeneous (on global scale) and isotropic. So rays of light can be observed moving along parallel trajectories in an expanding finite hypersphere. We show this implies an accelerated expansion of the Universe. Considering the energy conservation problem, also we argue about the necessity of matter-antimatter asymmetry.