  We study the effect of vortices on the tunneling decay of a symmetry-breaking
false vacuum in three spacetime dimensions with gravity. The scenario
considered is one in which the initial state, rather than being the homogeneous
false vacuum, contains false vortices. The question addressed is whether, and,
if so, under which circumstances, the presence of vortices has a significant
catalyzing effect on vacuum decay. After studying the existence and properties
of vortices, we study their decay rate through quantum tunneling using a
variety of techniques. In particular, for so-called thin-wall vortices we
devise a one-parameter family of configurations allowing a quantum-mechanical
calculation of tunneling. Also for thin-wall vortices, we employ the Israel
junction conditions between the interior and exterior spacetimes. Matching
these two spacetimes reveals a decay channel which results in an unstable,
expanding vortex. We find that the tunneling exponent for vortices, which is
the dominant factor in the decay rate, is half that for Coleman-de Luccia
bubbles. This implies that vortices are short-lived, making them cosmologically
significant even for low vortex densities. In the limit of the vanishing
gravitational constant we smoothly recover our earlier results for the decay of
the false vortex in a model without gravity.
