Decay of the false vacuum

Decay of the false vacuum: Since the universe is not inflating today, the inflationary theory depends on the fact that the false vacuum which drives inflation is metastable, so it will eventually decay. The theory requires that this decay happen after more than 100 doubling times of the exponential expansion, but it still happens when the universe is much less than one second old. If the inflation fields are in a local valley of the energy density diagram, then the decay happens via the formation of bubbles, like the boiling of water, and the randomness of the bubble formation destroys the homogeneity of the universe and causes the theory to fail. This failure is called the graceful exit problem of the original inflationary theory. lf however, the inflation field is at the top of a local plateau, as assumed in the new inflationary universe theory, then inflation continues as the fields roll gently towards a minimum energy value, and a single bubble becomes large enough to encompass the entire observed universe.