  We study the effect that initial state fluctuations have on final particle
correlations in heavy ion collisions. More precisely, we focus on the
propagation of initial perturbations on top of the expanding fireball using the
conformal solution derived by Gubser and Yarom for central collisions. For
small perturbations, the hydrodynamic equations are solved by separation of
variables and the solutions for different modes are added up to construct
initial point-like perturbations, that are then allowed to evolve until
freeze-out. The Cooper-Frye prescription is used to determine the final
particle distribution. We present the two-particle correlation functions and
their Fourier spectra obtained for different viscosities and different initial
widths of the perturbation. We find that viscosity kills the higher harmonics,
but that the Fourier spectra presents maxima and minima, similar to what is
seen in the study of cosmic microwave background radiation.
