One Bubble to Rule Them All

Understand

We apply the principles of quantum mechanics and quantum cosmology to predict probabilities for our local observations of a universe undergoing false vacuum eternal inflation.

• At a sufficiently fine-grained level, histories of the universe describe a mosaic of bubble universes separated by inflationary regions.
• We show that predictions for local observations can be obtained directly from sets of much coarser grained histories which only follow a single bubble.
• These coarse-grained histories contain neither information about our unobservable location nor about the unobservable large-scale structure outside our own bubble.