What will happen if every particle of our universe expanded beyond three dimensions of our classical space?

Additional invisible dimensions would collapse on themselves, on a scale of less than a billion?

A gigantic sphere, which causes matter to influence gravity like normal matter, but does not communicate electromagnetically with any light.

A dark world that coexists with ours like a kind of mirror world that has a bestiary of dark particles, previously attached to each other, rather than to a single type of dark matter.