From the link:
“Accordingly, our own Universe may be the interior of a black hole existing in another universe.” So concludes Nikodem Poplawski at Indiana University in a remarkable paper about the nature of space and the origin of time.
The idea that new universes can be created inside black holes and that our own may have originated in this way has been the raw fodder of science fiction for many years. But a proper scientific derivation of the notion has never emerged.
That means the universe as we see it today can be explained by a single theory of gravity without any additional assumptions about inflation.
Another important by-product of Poplawski’s approach is that it makes it possible for universes to be born inside the event horizons of certain kinds of black hole. Here, torsion prevents the formation of a singularity but allows a HUGE energy density to build up, which leads to the creation of particles on a massive scale via pair production followed by the expansion of the new universe.
This is a Big Bang type event. “Such an expansion is not visible for observers outside the black hole, for whom the horizon’s formation and all subsequent processes occur after infinite time,” says Poplawski.
For this reason, the new universe is a separate branch of space time and evolves accordingly.