Computations of spherical gravitational collapse using null slicing

Results are presented from a numerical study of spherical GR gravitational collapse using 'observer-time' null slicing. Data on the initial null slice are generated by computing collapse from an initial spacelike slice by means of a standard method and noting parameter values at successive grid points as they are passed by a hypothetical null ray propagating out from the centre. Collapse is then followed to black hole formation using the observer-time code.