SMOOTH METRICS FOR SNAPPING STRINGS

We construct two possible metrics for Abelian Higgs vortices with ends on black holes. We show how the detail of the vortex fields smooths o ut the nodal singularities which exist in the idealized metrics. A cor ollary is that apparently topologically stable strings might be able t o split by black hole pair production. We estimate the rate per unit l ength by references to related Ernst and C-metric instantons, concludi ng that it is completely negligible for GUT-scale strings. The estimat ed rate for macroscopic superstrings is much higher, although still ex tremely small, unless there is an early phase of strong coupling.