  Electrostatic interactions play an important role in numerous self-assembly
phenomena, including colloidal aggregation. Although colloids typically have a
dielectric constant that differs from the surrounding solvent, the effective
interactions that arise from inhomogeneous polarization charge distributions
are generally neglected in theoretical and computational studies. We introduce
an efficient technique to resolve polarization charges in dynamical dielectric
geometries, and demonstrate that dielectric effects \emph{qualitatively} alter
the predicted self-assembled structures, with surprising colloidal strings
arising from many-body effects.
