Nikodem Poplawski thinks he has proven that our universe could have originated in a medium sized black hole.
Poplawski's recently published paper shows that using the Einstein-Cartan-Sciama-Kibble theory of gravity, gravitational collapse of spin-ﬂuid fermionic matter in a black hole of intermediate mass forms a new universe of about 1026 solar masses.
He used the Einstein-Cartan-Sciama-Kibble (ECSK) theory of gravity, which naturally extends the general theory of relativity to account for the quantum-mechanical, intrinsic angular momentum (spin) of elementary particles that compose gravitating matter.
In the presence of fermions, which compose all stars in the Universe, mathematically speaking, spacetime torsion does not vanish because Dirac ﬁelds couple minimally to the torsion tensor. At macroscopic scales, such particles can be averaged and described as a spin ﬂuid.
The gravitational repulsion in the spin-ﬂuid fermionic matter becomes signiﬁcant at extremely high densities that existed in the early Universe and exist inside black holes. It prevents a cosmological singularity, replacing it by a state of minimum but ﬁnite radius.
This extremely hot and dense state is a bounce that follows the contracting phase of the Universe and initiates its rapid expansion.
Torsion therefore provides a natural way to explain what caused such an expansion and what existed before the Universe began to expand.
In fact, the observed scale-invariant power spectrum of cosmological perturbations is, in principle, consistent with a scenario in which our Universe was born in a black hole.