https://en.m.wikipedia.org/wiki/Conformal_cyclic_cosmology

It seems the paper made mistakes, using a non-standard model of the CMB that failed upon replication. It's an interesting theory thoughb.

As a non-Physicist, I absolutely love the CCC hypothesis and I really hope it turns out to be true. It seems like such a beautiful alternative to the idea of the heat death of the universe just lasting forever and nothing ever happening again.