Within 200 years, this simulation forms a large coherent lump about halfway out in the disk which has about 30 times the mass of Jupiter. Dr. D.'s group does not like Alan Boss's assumptions. This simulations shows what happens when the assumption that the disk does not expand is relaxed. In fact, there is no good physical reason to believe that the disk will not expand. Instead of dense lumps, the disk forms somewhat dense spiral arms.
Interesting things happen to the disk but no planets or brown dwarfs form directly.
Here, Dr. D's group also relaxes the assumption that clumping gas stays cold. Now even the spirals do not get dense. Heating by compression creates pressure which keeps the gas from condensing too much. Dr. D.'s group feels that this simulation is much closer to the way a REAL disk would behave. Based on these simulations, Dr. D.'s group concludes that planets and brown dwarfs probably do not form in the way Alan Boss proposes.