  Although the time profiles of gamma ray bursts (GRBs) show extremely diverse
behavior, their average statistical properties such as the average peak-aligned
profile and the auto-correlation function show simple stretched-exponential
behavior. This could indicate that the diversity of all bursts is just due to
different random realizations of the same simple stochastic process where the
process is scale invariant in time. We illustrate how both the diversity of GRB
time profiles and some important average statistical properties can be
reproduced in this way using a simple toy model for a stochastic pulse
avalanche, which behaves as a chain reaction in a near-critical regime. We
suggest that one possibility for the underlying physical process for generating
GRBs could be a chain detonation in which reconnecting magnetic turbulent
features trigger each other.
