5 Numerical Hydrodynamics on Null Cones
Numerical evolution of relativistic hydrodynamics has been traditionally carried out on spacelike
Cauchy hypersurfaces. Although the Bondi-Sachs evolution algorithm can easily be extended to
include matter [137], the advantage of a light cone approach for treating fluids is not as apparent
as for a massless field whose physical characteristics lie on the light cone. However, results
from recent studies of relativistic stars and of fluid sources moving in the vicinity of a black
hole indicate that this approach can provide accurate simulations of astrophysical relevance
such as supernova collapse to a black hole, mass accretion, and the production of gravitational
waves.