  The effect of initial state fluctuations on jet energy loss in relativistic
heavy-ion collisions is studied in a 2+1 dimension ideal hydrodynamic model.
Within the next-to-leading order perturbative QCD description of hard
scatterings, we find that a jet loses slightly more energy in the expanding
quark-gluon plasma if the latter is described by the hydrodynamic evolution
with fluctuating initial conditions compared to the case with smooth initial
conditions. A detailed analysis indicates that this is mainly due to the
positive correlation between the fluctuation in the production probability of
parton jets from initial nucleon-nucleon hard collisions and the fluctuation in
the medium density along the path traversed by the jet. This effect is larger
in non-central than in central relativistic heavy ion collisions and also for
jet energy loss that has a linear than a quadratic dependence on its path
length in the medium.
