Bubbling the false vacuum away

We investigate the role of nonperturbative, bubblelike inhomogeneities on the decay rate of false-vacuum states in two- and three-dimensional scalar field theories. The inhomogeneities are induced by setting up large-amplitude oscillations of the field about the false vacuum, as, for example, after a rapid quench or in certain models of cosmological inflation. We show that, for a wide range of parameters, the presence of large-amplitude bubblelike inhomogeneities greatly accelerates the decay rate, changing it from the well-known exponential suppression of homogeneous nucleation to a power-law suppression. It is argued that this fast, power-law vacuum decay—known as resonant nucleation—is promoted by the presence of long-lived oscillons among the nonperturbative fluctuations about the false vacuum. A phase diagram is obtained distinguishing three possible mechanisms for vacuum decay: homogeneous nucleation, resonant nucleation, and crossover. Possible applications are briefly discussed.