Question: Isn’t it possible that the answer to the increasing speed of the expansion of the Universe is that it is being pulled apart not being pushed apart? If the “unknown” Universe was trillions of light years of dark energy and when the “singularity” appeared, it would have exploded, for lack of a better term, inflation would have occurred, then as gravity was created, the expansion would have slowed down but as the years have gone by the power of all that dark energy, as thin as it is, will eventually overcome the gravity contained in the “known” Universe and pull it into oblivion. – Philip
Answer: To suggest that the accelerating expansion of the universe is caused by a “pulling” force rather than a “pushing” force would require identifying the source of the “pulling”. Dark energy is theorized to be a component of the known universe that we had not originally appreciated. If one wants to incorporate an external force, then one needs to identify from where this force came, which is the difficult part.