If parellel universes exist, then their parameters are unknown and it is all just a guess at this point.
It is the most popular theory currently in the spotlight that space is multidimensional.
Nothing about it has been proven. No predictions produced by the theory have been made.
It could all turn out to be a big theory of nothing.
There are other theories of what reality is where there are no dimensionally parellel universes.
Unfortunatly, much of mainstream science is still practiced like a faith based religion.
They embrace parellel universe theory, for which there is absolutly no evidence.
And deny the possibility of UFO's being of alien origin, for which there is a great deal of evidence.
Whatever works, use it.
A good idea stands on its own value independent of authorship.
If it stands or falls on the credibility of the author, maybe it isn't such a good idea.