Just a simple statement of obviousness ...
If the 'universe' actually does bend back on itself so there really is no 'edge' defining it's limit, then one has a priori proclaimed/established that there can be no such thing as 'other universes', because, per argument, the one universe we live in is everything there is, it is unlimited, infinite - the lack of an 'edge' 'proves' it.
QED
Now, chew on that one fur a few milliparsecs, afore goin on another tang-end.
The universe is one giant mobius strip.