  Medium-induced gluon radiation gives rise to the strong energy-loss observed
in single-hadron spectra in heavy-ion collisions. Its angular structure,
leading e.g. to intra-jet correlations, is only known for the one-gluon
inclusive case. In the vacuum, properties such as angular ordering appear when
considering less inclusive distributions due to destructive interference
effects. We present a calculation which takes into account interference effects
in a medium for a setup in which we consider gluon radiation off a
quark-antiquark pair with a given opening angle. Surprisingly, computing the
spectrum at leading-log accuracy we find that an ordering exists which is
exactly opposite from that in the vacuum. We estimate the magnitude of the
effect along with a discussion of the implications of such "anti-angular
ordering" on jet physics in heavy-ion collisions.
