Nope QED infinte and flat aren’t the same thing, you can have a flat universe of finite spatial extent, our universe is thought to be of infinite spatial extent.
An open universe is a Friedmann-Lemaitre cosomological model in which space is infinte and of negative (Euclidian) curvature and will contiune to exapnd.
Squink quotes Alan Hunt, a cosmologist (apparently), as saying the universe evolved from just 25 pounds of mass, and nobody here bats an eye.
Oy!
I guess I should be glad none of you has mentioned the possibility of an infinite number of other universes.
As I said before the current cosmological model has the universe as infinte and forever expanding, there are sevral models, one which used to favoured up until a few years ago (hence the confusion) where the universe is spatially finite and the curvature of the universe means it forms a sort of hypersphere, in otherwords it has no centre or edges.