  At nonzero chemical potential the numerical sign problem in lattice field
theory limits the use of standard algorithms based on importance sampling.
Complex Langevin dynamics provides a possible solution, but it has to be
applied with care. In this review, we first summarise our current understanding
of the approach, combining analytical and numerical insight. In the second part
we study SL(N,C) gauge cooling, which was introduced recently as a tool to
control complex Langevin dynamics in nonabelian gauge theories. We present new
results in Polyakov chain models and in QCD with heavy quarks and compare
various adaptive cooling implementations.
