It depends on ones definition of "universe"

1) if we say the universe is everything, there can be no "twin universe"
multiple universes or whatever you will call it
everything will also include other dimensions, everything means everything!
2) if we say the universe are a part of cosmos, yes you can have more than 1
universe

so you need to make a decision, otherwise you speek nonsens

"G=EMC^2 Glazier" skrev i en meddelelse
...
My own idea is universes are exactly the same right down to their number
of electrons. Should that no be reality I have to go with that some
universes that are different have the structure of all iron atoms bert