Conformal diagrams for the gravitational collapse of a spherically   symmetric dust cloud
  We present an algorithm for the construction of conformal coordinates in the interior of a spherically symmetric, collapsing matter cloud in general relativity. This algorithm is based on the numerical integration of radial null geodesics. As an application we generate conformal diagrams for collapsing spherical dust clouds and analyze the causal structure of the resulting spacetimes. 
N\'estor Ortiz and Olivier Sarbach
gr-qc