  Combining hydrodynamic planet-disk interaction simulations with dust
evolution models, we show that protoplanetary disks having a giant planet can
reveal diverse morphology in (sub-)millimeter continuum, including a full disk
without significant radial structure, a transition disk with an inner cavity, a
disk with a single gap and a central continuum peak, and a disk with multiple
rings and gaps. Such a diversity originates from (1) the level of viscous
transport in the disk which determines the number of gaps a planet can open;
(2) the size and spatial distributions of grains determined by the coagulation,
fragmentation, and radial drift, which in turn affects the emmisivity of the
disk at (sub-)millimeter wavelengths; and (3) the angular resolution used to
observe the disk. In particular, our results show that disks having the same
underlying gas distribution can have very different grain size/spatial
distributions and thus appearance in continuum, depending on the interplay
among coagulation, fragmentation, and radial drift. This suggests that proper
treatments for the grain growth have to be included in models of protoplanetary
disks concerning continuum properties and that complementary molecular line
observations are highly desired in addition to continuum observations to reveal
the true nature of disks. The fact that a single planet can produce diverse
disk morphology emphasizes the need to search for more direct, localized
signatures of planets in order to confirm (or dispute) the planetary origin of
observed ringed substructures.
