If it accumulates this material quickly enough, the gaseous atmosphere may become too massive and collapse, beginning a rapid gas accretion phase forming a gas giant. (seeker.com)
The riddle posed by super-Earths (1 — 4 Earth radii, 2 — 20 Earth masses) is that they are not Jupiters: their core masses are large enough to trigger runaway gas accretion, yet somehow super-Earths accreted atmospheres that weigh only a few percent of their total mass. (eos-nexus.org)
Black holes have to start out much larger initially in order to grow into the supermassive black holes at the centers of galaxies that we see today, unless we are missing some fundamental physics in our understanding of gas accretion. (kavlifoundation.org)