  The contribution presents a brief summary of the Gauge/Gravity approach to
the study of hydrodynamic flow of the quark-gluon plasma formed in heavy-ion
collisions, in a boost-invariant setting (Bjorken flow). Considering the ideal
case of a supersymmetric Yang-Mills theory for which the AdS/CFT correspondence
gives a precise form of the Gauge/Gravity duality, the properties of the
strongly coupled expanding plasma are put in one-to-one correspondence with the
metric of a 5-dimensional black hole with the horizon moving away in the 5th
dimension and its deformations consistent with the relevant Einstein equations.
Several recently studied aspects of this framework are recalled and put in
perspective. New results in collaboration with G.Beuf and M.Heller on the early
time expansion towards the hydrodynamical regime are provided giving a new
insight on the far-from-equilibrium behavior of the fluid at strong coupling
and the thermalization and isotropization problems.
