Gravitational collapse of a fluid with torsion into a universe in a
  black hole
  We consider gravitational collapse of a spherically symmetric sphere of a
fluid with spin and torsion into a black hole. We use the Tolman metric and the
Einstein--Cartan field equations with a relativistic spin fluid as a source. We
show that gravitational repulsion of torsion prevents a singularity and
replaces it with a nonsingular bounce. Quantum particle production during
contraction helps torsion to dominate over shear. Particle production during
expansion can generate a finite period of inflation and produce enormous
amounts of matter. The resulting closed universe on the other side of the event
horizon may have several bounces. Such a universe is oscillatory, with each
cycle larger in size then the previous cycle, until it reaches the cosmological
size and expands indefinitely. Our universe might have therefore originated
from a black hole.
