Critical phenomena in the aspherical gravitational collapse of radiation fluids

Gravitational critical collapse describes the scaling of the mass of the black hole as a function of the difference of a parameter from its critical value. When above this critical value, collapse leads to black hole formation with the mass exhibiting a characteristic (Choptuik) scaling. This careful study marks the beginning of the exploration of non-spherical (for example, spinning) collapse, which has remained very poorly understood.