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Is there any theory in the literature that supports this hypothesis that BHs in their center do not have a super-dense matter singularity but are pure deformations in the fabric of spacetime itself or vacuum space, possible caused after supernova or other violent event or maybe preexisted as features or defects of spacetime or vacuum space long before any matter creation in the Universe?

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    $\begingroup$ A BH is completely characterized by its mass, charge, and spin, by the no-hair theorem. In this case mass must play a role as two otherwise identical BHs can be told apart from only their masses. $\endgroup$ May 15, 2022 at 11:53
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    $\begingroup$ What is your definition of a "pure deformation in the fabric of spacetime itself" ? How exactly would this differ from a black hole caused by a concentration of mass/energy ? $\endgroup$
    – gandalf61
    May 15, 2022 at 12:00
  • $\begingroup$ @gandalf61 Nice question. My definition is the absence of spacetime or vacuum space inside the event horizon of a BH. As the fabric of spacetime was missing, absolute nothing not even vacuum space. A hole in space would effectively mimic the increased gravity of a large mass thus the curving of spacetime. Extreme curvature in spacetime could not be caused exclusively by the presence of mass but may be a defect of the otherwise smooth spacetime. Similar to quantum vortices in a superfluid. $\endgroup$
    – Markoul11
    May 15, 2022 at 13:29
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    $\begingroup$ You may be interested in the concept of Primordial Black Holes $\endgroup$
    – RC_23
    May 15, 2022 at 15:27
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    $\begingroup$ @Markoul11 "a super-dense matter singularity" - This is a nonsense pushed by the popular press. The Schwarzschild singularity is not an object in space, but a moment of time, which never happens (a singularity is not a part of spacetime, see the correct answer by emacs drives me nuts below). Plus the Schwarzschild singularity is not a point, but an infinitely long line. So the "infinite density" of a singularity (even if asymptotically) is just as meaningless and an infinite density of a poinlike electron. $\endgroup$
    – safesphere
    May 16, 2022 at 4:11

2 Answers 2

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Is there any theory in the literature that supports this hypothesis that BHs in their center do not have a super dense matter singularity but are pure deformations in the fabric of spacetime itself or vacuum space

It's the General Theory of Relativity. The Schwarzschild solution for non-rotation, non-charged black holes is a vacuum solution, that is, the space is empty (vacuum): There's no matter and no radiation and no electric fields etc. anywhere.

The singularity itself is not a part of such spacetimes / solutions of Einstein's field equations. This means it is not correct and it makes no sense so say "there's a singularity of inifitit dense matter at the center of a BH", because the center is not a part of the space-time.

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Your explanation in your comment:

My definition is the absence of spacetime or vacuum space inside the event horizon

will not work. If this were correct then the whole event horizon would be a single point in spacetime i.e. it would in effect have zero radius. In this case photons (which follow geodesics in spacetime) would be reflected from the event horizon, and to an outside observer the event horizon would show some distorted image of the black hole’s surroundings. But we know from the EHT images that the event horizon of a black hole is (as expected) black.

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  • $\begingroup$ This answer makes no sense. It is a perfectly valid assumption that no spacetime exists inside the event horizon. This assumption does not cause the effects mentioned in this answer or any other effects whatsoever and thus cannot be disproven in theory or by an external experiment. In the original Schwarzschild solution, the radius of the horizon is zero with no spacetime "inside" it. $\endgroup$
    – safesphere
    May 16, 2022 at 3:46
  • $\begingroup$ @safesphere The Schwarzschild metric has a removable singularity at the Schwarzschild radius $r_s=\frac{2GM}{c^2}$ which corresponds to the event horizon, but it is well defined for all non-zero values of $r$ both less than and greater than $r_s$. It certainly does not suggest there is no spacetime for $r<r_s$. See en.wikipedia.org/wiki/Schwarzschild_metric. $\endgroup$
    – gandalf61
    May 16, 2022 at 5:28

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