COSMIC CENSORSHIP IN 2-DIMENSIONAL DILATON GRAVITY

The global structure of two-dimensional dilaton gravity is studied, at tending in particular to black- holes and singularities. A gravitation al energy is defined and shown to be positive at spatial singularities and negative at temporal singularities. Trapped points are defined, a nd it is shown that spatial singularities are trapped and temporal sin gularities are not. Thus a local form of cosmic censorship holds for p ositive energy. In an analogue of gravitational collapse to a black ho le, matter falling into an initially flat space creates a spatial curv ature singularity which is cloaked in a spatial or null apparent horiz on with non-decreasing energy and area.