New solution found: Black holes might be dark stars with layers (PDF preprint)

Black holes are normally and naturally associated to the end-point of gravitational collapse. Yet, alternatives have been proposed and a particularly interesting one is that of gravitational condensate stars, or gravastars. We here revisit the gravastar model and increase the degree of speculation by considering new solutions that are inspired by the original model of gravastars with anisotropic pressure, but also offer surprising new features.

Apparently for mainstream scientists things and models can become realistic only when they formal solution for them (and once such a solution is found, they adhere on it like hungry hens on their feeders because they provide jobs for them). But Nature primarily follows robust predicate logics and geometry instead of contrived solutions based on fragile low-dimensional models. Given the fact that dense neutron stars can be also surrounded by event horizon, there is seamless transition between dense stars and black holes. It also follows AWT scenario, in which black holes are formed by condensation of dark matter and they also evaporate to dark matter (scalar waves and neutrinos) first - gravitational waves are thus ripples of dark matter density.

The authors of the new paper point out that there isn’t just one type of gravastar, but that the same process can happen multiple times, forming shells within shells within shells in similar way like giant elementary particles. And interestingly enough, this makes the gravastars more stable. See also:

Deconstruction of general relativity model of black holes IV 1, 2, 3, 4, 5...