  The contribution presents a summary of the Gauge/Gravity approach to the
study of hydrodynamic flow of the quark-gluon plasma formed in heavy-ion
collisions. 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 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. This paper is a written version of the four
lectures given by the authors on that subject.
