I am mostly providing points to ponder. However, the “Big Bang” must, by reason and logic, have a “Big Banger.”
No?
Well, to answer your question honestly, I’d say “We don’t know.”
To expand on that, once again I will repeat that causation is a feature of our universe. Is it inherited from some previous or larger existence? If yes, then yes, the universe required a cause. If no, if the universe encapsulates causation; in other words, causation is a product of the Big Bang, then the answer is no, the universe does not require some impetus (whether that be a Prime Mover, or some larger reality like the multiverse).
But if we do invoke the notion that the universe required a cause, we then have to postulate that there was something before it (whatever “before” means), or more precisely that time, in some way, was a parameter or dimension before the Big Bang. Then we’re left asking “So, if not the Big Bang, then when?” And to my mind, simply declaring a Creator or a Multiverse or whatever solution you invoke doesn’t need a cause in turn, it sure looks to me like you invite either an infinite series of causes, or just a post hoc declaration with no other reason than to promote one’s pre-existing view.
I’m not sure we’ll ever be able to answer the question of how the Universe began. I’ve stated my view, that time is a curve that becomes steeper then further back you go, so that while the universe is of finite age, you never quite reach Time Zero, so a sort of infinite description of the finite. But if I go with the multiverse types, then we’re just talking about a multiverse, and where did THAT come from? The same problem comes from invoking God. Just declaring either one of these as being the uncaused cause of the universe strikes me as violating parsimony. I can just counter that the Universe is self-caused, which I have no more evidence for than a theistic or multiverse advocate can provide, but at least I’ve removed the extra entity and taking the attribute “uncaused” and moved it to the one entity I can say exists; the universe itself.