No, because it’s wrong. What general relativity predicts is that the Universe had a singularity in its past-which is what Hawking and Penrose proved. Black holes hava a singularity in their future.

Stam Nicolis

Thank you very much for your answer. I am attached to the fact that the universe could be a neutron. The singularity must then be defined.

The statement that the Universe could be a neutron is obviously wrong, at least since the discovery of the neutron in 1932.

The past singularity of the Universe doesn't have anything to do with the existence of point particles and the neutron isn't a point particle-it's a bound state of quarks, as is known since 1968.

Stam Nicolis

Many thanks for your prompt answer. Best regards.

“Can we think that general relativity rather predicted that the universe is a black hole?”

- this question has the clear answer - general relativity without some problems can predict that the universe can be a black hole; since in the GR the unique condition for existence of some “black hole” is that that is some material object that has mass, M, and radius, R, such, that the mass and the radius are related as R=GM/c2, where G is the gravitational constant, and c is the speed of light, in this case R is “Schwarzschild radius”;

- and the “event horizon radius”, since, as that follows from the GR equations, nothing that happens inside the sphere with this radius cannot escape from the sphere, since the escape velocity on the sphere surface is equal to the speed of light. [Defined by this condition radius of the surface in Newton Gravity “black hole” is two times lesser, RN=GM/2c2].

Correspondingly any mass can be “black hole”, if its mass and radius are in accordance with the GR equation above - including if “universe”, more correctly “Matter” has some limited mass, and its radius is the Schwarzschild one, then it is a black hole. Besides yeah, from cosmological observations doesn’t follow that that is impossible – and from some rather rational estimations of possible Matter’s mass and the radius values, since these estimations now are in rather wide range, follows that yeah, Matter is a black hole.

In that, again, would be nothing surprising, because of that the density inside black hole is ~1/R3. So, say, the “density of the Milky Way SMBH” is in ~104 times lesser than the density of neutron stars, which aren’t black holes, while the radius of the SMBH has rather cosmological value – ~8% of the distance Earth-Sun.

That is another thing, that in the GR the “black hole” is just the “hole in spacetime”, and so it is senseless to say something non-mystic about what can be in this “hole”, and into where this “hole” is open, etc.

Really, as that is rigorously proven in the 2007 Shevchenko-Tokarevsky’s “The Information as Absolute” conception, recent version of the basic paper see

https://www.researchgate.net/publication/363645560_The_Information_as_Absolute_-_2022_ed

- and more concretely in physics in the Shevchenko-Tokarevsky’s informational physical model, which is based on the conception,

- the Matter’s spacetime is the fundamentally absolute, fundamentally flat, and fundamentally “Cartesian”, [5]4D spacetime with metrics (cτ,X,Y,Z,ct), which fundamentally cannot be transformed, including curved, by anything in Matter; and, of course, in the spacetime any “holes” are fundamentally impossible; what are black holes really see

https://www.researchgate.net/publication/355361749_The_informational_physical_model_and_fundamental_problems_in_physics , section “Cosmology”. Including what is the Milky Way SMBH, where in the center really indeed some compact object with some extreme density is placed, while the rest volume under the SMBH’s “event horizon” has rather small density of the accretion disk continuation particles.

But, at that, Matter indeed can be “black hole”, and so being rather isolated in the spacetime above, while the dimensions of the spacetime are, by really scientific definitions of “space” and “time” [see the links] , fundamentally infinite, and so in this spacetime can exist infinite, and on infinite distances, any number of some other Matters that have identical with Matter’s ones designs and structures, i.e. which are based on the same ultimate base – the binary reversible fundamental logical elements [FLE];

- while in that this “black hole’s” density, in contrast to the observed black holes, isn’t concentrated in a central object, but is rather uniformly distributed, there is nothing surprising as well.

More see the links above.

Cheers

Sergey Shevchenko

Many thanks for the explanation and information. Kind regards.

As it happens, General Relativity predicted that the Universe should be collapsing (if its mass is greater than a critical value) or expanding (if its mass is less than that value. However, at the time that Einstein developed his theory, our galaxy was thought to be the entire Universe, and the existence of other galaxies, let alone the Universe as we now think of it, was unknown, and their existence became a matter of controversy years after Einstein published his theory. And since our galaxy is gravitationally self-bound and neither expanding nor contracting, he felt that there must be something wrong with his theory, and invented the meaningless constant "Lambda" to ensure that the Universe neither expanded and contracted. Later on, when it was realized that there were other galaxies, and that the Universe they inhabit is expanding, Einstein said that inventing "Lambda" was the biggest mistake of his career. Unfortunately, modern cosmologists tend to ignore that, and try to give Lambda and similar nonsense some kind of meaning, which of course they never will, so we will all live and die reading about all kinds of nonsense, and every now and then, a new proof that Einstein's original theory was right, after all.

Courtney Seligman

Many thanks for the details. Concerning the constant "Lambda" you said "And since our galaxy is gravitationally self-bound and neither expanding nor contracting, he felt that there must be something wrong with his theory, and invented the meaningless constant "Lambda" to ensure that the Universe neither expanded and contracted." Yes i'am sure that what you say about this constant "Lambda" is absolutely true. I find constant "Lambda" is a function of squared RA where c=HAxRA that is all. Therefore i also believe that constant "Lamda" has no sens as you say. But HA is very important. I believe that the value of HA=55.5 km/sec/Mpc is in close link with the value 67.4 km/s/Mpc (Planck resuls 2018). I believe that this latter value is the expansion rate of the early universe! I believe the value 72.4 km/s/Mpc (Freedman et al.) is very precise it should represent the constant of Hubble (local zone). I asked a question on RG but no one answer me. My question was "Do you think that the value 67.4 km/s/Mpc (Planck 2018 results) is in close link with HA (Einstein's equation c=HAxRA)?". Best regards.