  We study nonequilibrium dynamics of SU(2) pure gauge theory starting from
initial over-population, where intense classical gauge fields are characterized
by a single momentum scale Q_s. Classical-statistical lattice simulations
indicate a quick evolution towards an approximate scaling behavior with
exponent 3/2 at intermediate times. Remarkably, the value for the scaling
exponent may be understood as arising from the leading O(g^2) contribution in
the presence of a time-dependent background field. The phenomenon is associated
to weak wave turbulence describing an energy cascade towards higher momenta.
This particular aspect is very similar to what is observed for scalar theories,
where an effective cubic interaction arises because of the presence of a
time-dependent Bose condensate.
