  The gravitational instability model of planet/brown dwarf formation proposes
that protostellar discs can fragment into objects with masses above a few
Jupiter masses at large semimajor axis. Tidal downsizing may reduce both the
object mass and semimajor axis. However, most studies of tidal downsizing end
when the protostellar disc disperses, while the system is embedded in its
parent star-forming region. To compare disc fragment descendants with exoplanet
and brown dwarf observations, the subsequent dynamical evolution must be
explored.
  We carry out N-Body integrations of fragment-fragment scattering in
multi-object star systems, and star systems embedded in substructured clusters.
In both cases, we use initial conditions generated by population synthesis
models of tidal downsizing.
  The scattering simulations produce a wide range of eccentricities. The
ejection rate is around 25%. The ejecta mass distribution is similar to that
for all objects, with a velocity dispersion consistent with those produced by
full hydrodynamic simulations. The semimajor axis distribution after scattering
extends to parsec scales.
  In the cluster simulations, 13% of objects are ejected from their planetary
system, and around 10% experience significant orbit modification. A small
number of objects are recaptured on high eccentricity, high inclination orbits.
The velocity distribution of ejecta is similar to that produced by
fragment-fragment scattering.
  If fragment-fragment scattering and cluster stripping act together, then disc
fragmentation should be efficient at producing free-floating substellar
objects, and hence characterising the free-floating planet population will
provide strong constraints on the frequency of disc fragmentation.
