Several theories address this: Cosmic Rebirth: Some theories, like the cyclic universe model, propose that the universe undergoes endless cycles of expansion and contraction, meaning there is no ...

This is a measure of how clumpy matter is in the universe, and once again, different probes are yielding different results. Something in the ΛCDM model has to be wrong, but we're not sure what.

Analyzing this cosmic microwave background in high definition has allowed researchers to confirm a simple model of the universe and rule out many competing alternatives. | Credit: ACT ...