Suppose the following scenario:
You reside inside a huge stable spherical star with non-lethal environment at its core. The object is so huge and massive, that its radius is only slightly above its Schwarzschild radius.
Then the sphere is bombarded with high-density energy (sth. like neutron soup) from all sides, increasing the Schwarzschild radius to the point where an event horizon forms. All this would happen at the perimeter of your habitat, without you noticing it.
Are you now trapped inside an event horizon (I think, yes)?
Would your local metric change as soon as you "see" the horizon forming events? Or would it remain the same until the gravitational collapse "gets" you?
Would it in theory be possible to generate enough outward pressure to stop the gravitational collapse, i.e. is the pressure of gravitational collapse finite?
The motivation of this question is the description of spherical objects by an outer Schwarzschild metric and an inner part, which is "stapled", so that it fits and solves Einstein's equations. I always asked myself, whether there was a solution which stapled a non-vacuum metric to the Schwarzschild metric inside the event horizon.