A scenario is presented, based on renormalization group (linear perturbation)
ideas, which can explain the self-similarity and scaling observed in a
numerical study of gravitational collapse of radiation fluid. In particular, it
is shown that the critical exponent β and the largest Lyapunov exponent
Reκ of the perturbation is related by β=(Reκ)−1. We find the relevant perturbation mode numerically, and obtain
a fairly accurate value of the critical exponent β≃0.3558019, also
in agreement with that obtained in numerical simulation.Comment: 4 pages in ReVTeX, 2 uuencoded eps figures, uses BoxedEPSF.te