By the way the consensus by Astronomers is the Universe is flat and finite. What this means is if you shot off two photons in the same direction, they will always remain the same instance apart and eventually come back to their starting point. Mathematically, the shape is a donut (torus) but that’s used only for modelling purposes to explain what we see – not that the Universe is really shaped like a donut.
Dark Energy/Matter adds another “dimension” to all this. It’s possible Dark Energy is accelerating the expansion of the Universe, or at least will maintain the expansion so it will continue without stopping rather than the previous theory of the finite Universe eventually collapsing onto itself.
