Maybe a better analogy would be a spring that goes from contraction to expansion and back again? A lot of things behave like waves so could it be some space fie

Maybe a better analogy would be a spring that goes from contraction to expansion and back again? A lot of things behave like waves so could it be some space field swinging in a wave-like pattern? Is there some evidence for the expansion to have also happened say 10B years ago in the CMBR?