General conditions are developed for the formation of naked precursory (‘‘shell-focusing’’) singularities in spherical gravitational collapse. These singularities owe their nakedness to the fact that the gravitational potential fails to be single valued prior to the onset of a true gravitational singularity. It is argued that they do not violate the spirit of cosmic censorship. Rather, they may well be an essentially generic feature of relativistic gravitational collapse.

• Received 20 December 1991

DOI:https://doi.org/10.1103/PhysRevLett.68.3129