Some scientists are claiming so, based on an odd finding from Antarctica. Ethan Siegel isn’t isn’t taking the bait:
So where, in all of this, do the parallel Universes come in?
Because there were only three explanations for what ANITA saw: either there was an astrophysical source for these particles, there’s a flaw in their detector or their interpretation of the detector data, or something very exotic, remarkable, and beyond the Standard Model (known as CPT violation) is happening. Some very good science ruled out the first option (back in January), which means it’s almost certainly the second option. The third? Well, if our Universe cannot violate CPT, maybe this comes from a parallel Universe where CPT is reversed: an explanation that’s as unlikely as it is poorly reasoned.
Remember: in science, we must always rule out all the conventional explanations that don’t involve new physics before we resort to a game-breaking explanation.
Ethan Siegel, “Have we finally found evidence for a parallel universe?” at Forbes
The thing is, the parallel universe is out there for the same reason that the space aliens are out there; people need them. It won;t be very long before we are reading about the parallel universe again.
See also: Tales of an invented god