Abstract :
I review the motivation for considering the effect of the expansion of the medium produced in ultra-relativistic heavy ion collisions, on induced gluon radiation. Naive implementations of the effect of flow produce a marked asymmetry in radiation around the jet axis. Such asymmetry should be clearly visible in jet studies at the LHC. They also lead to an increase of the elliptic flow for high pT particles. As additional results, flow may mimic a larger transport coefficient i.e. a larger energy density of the medium, and the surface bias becomes weakened by expansion.
