Collective relaxation of stellar systems revisited
  The chaos in stellar systems is studied using the theory of dynamical systems
and the Van Kampen stochastic differential equation approach. The exponential
instability (chaos) of spherical N-body gravitating systems, already known
previously, is confirmed. The characteristic timescale of that instability is
estimated confirming the collective relaxation time obtained by means of the
Maupertuis principle.
