[michellemfry]

First, you only asked if such a thing were possible. Second, if waves and wavefronts are not the answer then why do we imagine the expanding space as a large phenomenon while the cause of such a thing is never considered to be small. Drop a stone in the center of a body of water and watch the wavefronts. Drop dark matter in the center and the wavefronts should accelerate, and oops they do. Well what do you know? Could it be possible?