feel that the gas needed for Core Accretion may not linger in the
disk long enough.
In the theory of ‘Gravitational Instability’,
gravity causes the disk of gas and dust to collapse into dense clouds,
which shrink and form solid cores within a few thousand years. The
rest of the cloud contracting to form the gas giant around the core
could take less than a million years.
If more giant extrasolar gas planets continue
to be found, this would imply that they regularly win the race against
this erosion of the disk.