  In this work we explore a new dynamical path for the delivery of
low-inclination comets. In a configuration formed by an interior giant planet
and an exterior massive debris disk, where the mass is accounted for by the 50
largest objects in the disk, the strongest mean motion resonances of the giant,
located along the belt, are replenished with new material (test particles) due
to the influence of the 50 massive objects. Once in resonance, slow chaotic
diffusion stirs the orbital elements of the cometary nuclei enough to encounter
the giant and to be scattered by it. When the disk is massive enough, both
resonant and non-resonant particles are stirred quickly to encounter the giant
and form an scattered disk component, greatly increasing the rate for the
delivery of cometary material to the inner part of the system. This mechanism
is applicable both to the solar system and extrasolar systems in general.
Preliminary results, using a disk as massive as the classical Kuiper belt,
indicate that the mechanism here proposed can account for about a tenth of the
required injection rate to maintain the population of ecliptic comets in steady
state. In a more massive belt of 0.25 M$_\oplus$, an estimated rate of around
0.6 new comets per year is found. Such a high rate would pose a serious risk
for the habitability of rocky interior planets, yet would resemble the late
heavy bombardment that was present in the early solar system.
