  In a holographic approach, the evolution of a 4D strongly coupled non-Abelian
plasma towards equilibrium can be studied investigating a 5D gravitational
dual. The process driving the plasma out-of-equilibrium can be described by
boundary sourcing, a deformation of the boundary metric; the analysis of the
late-time dynamics allows to understand how the hydrodynamic regime settles in.
We apply the method to a boost-invariant case, considering the effects of
different quenches, solving the Einstein equations in the bulk and studying the
time-dependence of observables such as the effective temperature, the energy
density and the pressures.
  The main outcome is that, if the effective temperature of the system when the
quench is switched off is $T_{eff}(\tau^*)=500$ MeV, thermalization is reached
within a time of ${\cal O}$(1 fm/c), an important information if the case of
the QCD plasma produced in relativistic heavy ion collisions is considered.
