Non-Abelian plasma instabilities may be responsible for the fast apparent
quark-gluon thermalization in relativistic heavy-ion collisions if their
exponential growth is not hindered by nonlinearities. We study the real-time
evolution of instabilities in an anisotropic non-Abelian plasma with an SU(2)
gauge group in the hard-loop approximation. We find exponential growth of
non-Abelian plasma instabilities both in the linear and in the strongly
nonlinear regime, with only a brief phase of subexponential behavior in
between.Comment: 4 pages REVTEX4, 3 figures; updated to match version published in
Phys. Rev. Lett. (shorter introduction, added details on quality of numerical
simulation