According to the theory proposed by scientists, our universe may have a double, which is “behind” the big bang, and there time is running backwards.
In physics, 3 fundamental symmetries are known, the same as CPT symmetry: charge (C) – in case of exchange of charges of interacting particles, the interaction itself remains the same; Correspondence (P) — when changing the spatial coordinates, we still get the same mirror image; Time (T) — the forward and backward flow of time is the same.
In a new paper, available on the scientific portal arXiv, the researchers say that we can extend this set of symmetries not just to certain interactions, but to the cosmos as a whole.
This leads to an “anti-universe” that balances its own double. And if this is indeed the case, what do we get as a result?
First, such a universe is naturally expanding and filled with particles, which does not require inflation (see the article: First there was inflation – how the universe came to be and what happened before the big bang). Although there is a lot of evidence for inflation, the overall picture is still very vague and allows for alternative assumptions to be made.
The second issue concerns the neutrino, a light particle that exists in 3 forms: electronic, muonic, and tauonic. All of them rotate to the left, and the rest of the particles rotate to both sides. Accordingly, physicists consider the existence of another kind of neutrino. In the twin of our universe, there must be at least one similar species that “speaks the language of gravity”, although it will be difficult for us to detect them through physical experiments. Considering the listed characteristics, it is quite possible that they formed neither more nor less dark matter.
The authors suggest that all three types of neutrinos should be majoran, i.e. their own antiparticle (for comparison, they call them positrons, as opposed to ordinary electrons, for example), and one of them should not have a mass. This means that if the mass of these particles is ever investigated and the “black sheep” is found, the idea of the symmetry of the universe will become more plausible.
Finally, in such a cosmos, inflation, which “shaken” the space-time with gravitational waves, is excluded. If we cannot trace such primary waves, this also indicates the correctness of the mirror model.