  The observational properties of brown dwarfs pose challenges to the theory of
star formation. Because their mass is much smaller than the typical Jeans mass
of interstellar clouds, brown dwarfs are most likely formed through secondary
fragmentation processes, rather than through the direct collapse of a molecular
cloud core. In order to prevent substantial post-formation mass accretion,
young brown dwarfs must leave the high density formation regions in which they
form. We propose here that brown dwarfs are formed in the circumbinary disks.
Through post-formation dynamical interaction with their host binary stars,
young brown dwarfs are either scattered to large distance or removed, with
modest speed, from their cradles.
