  We investigate the fate of a relativistic star cluster with a dense core
which is undergoing a gravothermal catastrophe and is far from thermodynamic
equilibrium. Nonlinear cooperative contributions are included in the standard
transport equations for the last stage of evolution of a highly dense core of
stellar remnants. We find that the core redshift does not necessarily increase
without limit as the core becomes increasingly dense, preventing collapse to a
black hole. In particular, the redshift can remain less than the critical value
for relativistic collapse, resulting in a stable, massive dark core with a
Newtonian mantle and halo.
