  We present results from a jet energy loss calculation using the
Gyulassy-Levai-Vitev (GLV) formalism and bulk medium evolution from the
covariant transport model MPC. At both RHIC and LHC energies we find that
realistic transverse expansion strongly reduces elliptic flow at high pT
compared to calculations with transversely 'frozen' profiles. We argue that
this is a generic feature of GLV energy loss. Transverse expansion also leads
to stronger high-pT suppression, while fluctuations in energy loss with the
location of scattering centers weaken the suppression. But, unlike the
reduction of v2, these effects nearly disappear once alpha_s is adjusted to
reproduce R_AA in central collisions.
