Assuming the following
A universe is the surface from a bubble in hyperspace. Inside a bubble there is nothing, only the surface represents a universe. The size of the bubble is time.
Dark matter and dark energy is from bubbles different then our own bubble that only shares gravity.
The big bang are bubbles colliding, creating a other bubble.
My problem is if bubbles do only share gravity why would they have a collision, I expect that they would just pass trough each other without creating a big bang?