VACUUM DECAY AND INTERNAL SYMMETRIES

We study the effects of internal symmetries on the decay by bubble nuc leation of a metastable false vacuum. The zero modes about the bounce solution that are associated with the breaking of continuous internal symmetries result in an enhancement of the tunneling rare into vacua i n which some of the symmetries of the initial state are spontaneously broken. We develop a general formalism for evaluating the effects of t hese zero modes on the bubble nucleation rate in both flat and curved space-times.