This an attempt to improve my recent question What happens to the singularities of two black holes in the moment they merger?. What is the background talking about „singularities“ or „masses in the center?“ In Schwarzschild black holes and astrophysical black holes (Oppenheimer Snyder collapse) the mass is in the singularity which is a point in time and not part of the manifold. „Mass in a point“ means that General Relativity breaks down (keywords here are infinite curvature and geodesic incompleteness) and so the challenging question is how to avoid the singularity so that the mass is in the center somehow (planck scale) and not in a point. Such black holes are called „physical“ or „real“ black holes sometimes.
The answer could be loop quantum cosmology. There are numerous papers, .e.g this one:
We find the novel result that all strong singularities are resolved for arbitrary matter. … The effective spacetime is found to be geodesically complete for particle and null geodesics in finite time evolution. Our results add to a growing evidence for generic resolution of strong singularities using effective dynamics in loop quantum cosmology by generalizing earlier results on isotropic and Bianchi-I spacetimes.
Now what happens in the moment of the mergering? It seems quite clear that in the classical case (Schwarzschild black hole) the newly formed black hole being strongly deformed though has one singularity. Can we assume the same for real black holes whith their masses in the center? But how then do we explain that two seperately located masses are unified instantaneously? Is it more reasonable to assume the the two masses move towards to each other during the ringdown? Any clarification will be highly appreciated.