Scientists proved that the universe could not be born without the Big Bang

© Photo : V. Springel, Max-Planck Institut für Astrophysik, Garching bei MünchenКомпьютерная model «web» of the UniverseScientists proved that the universe could not be born without the Big Bang© Photo : V. Springel, Max-Planck Institut für Astrophysik, Garching bei München

The universe could only have been born in the Big Bang, as all alternative scenarios of its formation lead to the immediate collapse of the newborn Universe and its destruction, according to a paper published in the journal Physical Review D.

«All these theories were developed in order to explain the original «smooth» structure of the Universe at the time of her birth, and to estimate the initial conditions of its formation. We have shown that in fact they produce the opposite pattern – they occur powerful disturbances which ultimately lead to the collapse of the entire system,» write Jean-Luc Lehners (Jean-Luc Lehners) from the Institute for gravitational physics in Potsdam (Germany) and his colleagues.

The majority of cosmologists believes that the universe began from a singularity, began to expand rapidly in the first moments after the Big Bang. Another group of astrophysicists believed that the birth of our Universe was preceded by the death of her «ancestress», which probably happened during the so-called «Big Break».

The main problem with these theories is that they are incompatible with the theory of relativity – at a time when the universe was a dimensionless point, she was supposed to have infinite energy density and curvature of space and inside it was supposed to be a strong quantum fluctuations, which is impossible from the point of view of the offspring of Einstein.

To solve this problem, scientists have developed over the past 30 years, several alternative theories in which the universe is born in the other, less extreme conditions. For example, Stephen Hawking and James hartle 30 years ago suggested that the universe was a point not only in space but also in time to the birth time, in our sense of the word, simply did not exist. When the time came, the space was already relatively flat and homogeneous in order to be able to be «normal» universe with the «classical» laws of physics.

In turn, the Soviet-American physicist Alexander Vilenkin believes that our universe is a kind of «bubble» of false vacuum inside the eternal and ever-expanding giant multi-Universe, where ever there are similar bubbles in the result of the quantum fluctuations of the vacuum, being born literally out of nothing.

Both these theories allow to bypass the issue «beginning of time» and of the incompatibility of the conditions of the Big Bang from Einstein’s physics, but they put a new question – able whether such variants of expansion of the Universe to produce it in the form in which it now exists?

According to calculations Liners and his colleagues, in fact, similar scenario, the birth of the Universe can’t work in principle. In most cases, they lead not to the birth of «flat» and calm of the Universe, similar to ours, and by the appearance of strong perturbations in its structure that would make such «alternative» Universes unstable. Moreover, the probability of having such an unstable Universe is much higher than its stable counterparts, which casts doubt on the ideas of Hawking and Vilenkin.

Accordingly, the Big Bang is inevitable – scientists, how they make Liners and his colleagues will have to find a way to reconcile quantum mechanics and relativity, and also to understand how quantum fluctuations is suppressed at extremely high density of matter and curvature of space-time.