""I believe Olivier that all is a question of philosophy about the origin of this universe. The actual researchs inside our theoretical community consider mainly the photons osciilating vibrating and this GR. They utilise the geometrical algebras like hopf, clifford or Lie and the strings or the geometrodynamics to explain the topologies, geometries and they create extradimensions like in the strings with 10D, 11D,26D""
it is not my opinion....and im not the only one... !!!
see : https://arxiv.org/abs/gr-qc/9310026
Since further discussion of this 4 dimensional problem becomes a bit intricate it is illustrative to remove one dimension and treat space as 2 dimensional, space-time as 3 dimensional.
"""On a Planckian scale, our world is not in 3 + 1 dimensions. On the contrary, the degrees of observable freedom can best be described as if they were defined Boolean variables on a two-dimensional network, evolving over time. This observation, deduced from nothing less than arguments of unitarity, entropy and many other arguments"""
""Therefore I prefer not to speculate that quantum mechanics breaks down at the Planck scale, but in stead to suspect that quantum mechanics becomes trivial there: quantum superpositions are still allowed there but become irrelevant.""
Even though the problems just mentioned are grave and conceptually difficult to disentangle, they do not seem to be insurmountable.
Our basic problem is that there seem to be too many symmetry requirements and the Hilbert space of physically realizable states seems to be too small.
The picture we sketched of the 2+1 (or perhaps it is better to say 2+2) dimensional nature of our micro-universe seems to follow from quite general arguments. Rejecting any of these arguments leads to quite different and perhaps equally if not more difficult problems, and one cannot help observing that one's preferences seem to be related to nearly religeous prejudices. Besides the author not many other physicists have tried this particular avenue. We advocate its further persuit.
The emergence of a Hilbert space with a Copenhagen interpretation of its inner products is a quite natural feature of any theory with the following characteristics at a local scale:
the system must have discrete degrees of freedom at tiny distance scales, and the laws of evolution must be reversible in time.
With discrete degrees of freedom one can construct Hilbert space in a quite natural way by postulating that any state of the physical degrees of freedom corresponds to an element of a basis of this Hilbert space[1].
Reversibility in time is required if we wish to see a quantum superposition principle: the norm of all states is then preserved, even if they are quantum superpositions of these basis elements
We conclude that one has to attribute the black hole entropy not to the space-time metric itself but to the quantized fields present there (which of course does include the small quantum fluctuations of the metric itself), and then one must choose a cut-off sufficiently close to the horizon such that it exactly matches the known black hole entropy (1).
In short, the black hole entropy includes the entropy of the quantized fields in its neighborhood