I find that a bit mis-leading. While IAAP, this is not my area. My understanding is the at the big bang there are a HUGE number of universes (the Multiverse) t

I find that a bit mis-leading. While IAAP, this is not my area. My understanding is the at the big bang there are a HUGE number of universes (the Multiverse) that are causally dis-connected, with different coupling constants for the forces and very different physics. Within our universe we have our physics, which includes QM, and one way of viewing QM is the many-worlds view.