I think you refer to the theory of [eternal inflation

tecnic universe. But thats a different road to travel.]1. Space is infinite in that model and eternally inflating for some magic reason.

For some magical reason, at some places inflation comes to a halt and a universe comes into being. It seems as local bubbles appear in which inflation is much less than in the rapid expanding surroundings.

For some magical reason in all these bubble pockets the laws of physics and amount of matter can vary. So this can give rise to different kinds of bubble universes. Some last like ours, and will be taken up in the bigger picture of the externally inflating space (presumably like ours in the far future. Some will live shortly and are almost immediately "taken up" again in the whole. Only to have added a tiny amount of matter.

Note that this is a bit similar to the pyro

I think you refer to the theory of eternal inflation. Space is infinite in that model and eternally inflating for some magic reason.

For some magical reason, at some places inflation comes to a halt and a universe comes into being. It seems as local bubbles appear in which inflation is much less than in the rapid expanding surroundings.

For some magical reason in all these bubble pockets the laws of physics and amount of matter can vary. So this can give rise to different kinds of bubble universes. Some last like ours, and will be taken up in the bigger picture of the externally inflating space (presumably like ours in the far future. Some will live shortly and are almost immediately "taken up" again in the whole. Only to have added a tiny amount of matter.

Note that this is a bit similar to the pyrotechnical universe but that's another road to travel.