Two CONICET scientists they showed that black holes can survive the contraction and expansion of the Universe, in a job that is part of a alternative model that discusses the Big Bang theory, reported the scientific body.
According to him cosmological model current standard, that is, the most accepted by the international scientific community that explains how it was the evolution of the universe from its beginnings and gives an account of how the different elements and structures that compose it were generated, the universe begins its expansion from a state of very high density and temperature, the Big Bang.
Current physical theories, however, are unable to explain the conditions of the universe, both prior to and just at the beginning of this state of expansion, so scientists around the world began to work on alternative cosmological models.
This is how the so-called rebound cosmologies arose, which postulate the existence of a very diluted universe with already formed structures, such as the one we know today, which by some process contracted to a certain point where it rebounded to start expanding.
In this line, a researcher and a researcher from the Conicet at the Argentine Institute of Radio Astronomy (IAR, CONICET-UNLP-CICPBA) embarked on the task of studying what type of objects could survive this stage of contraction and rebound of the universe.
“If we have an already formed universe, with galaxies, planets, black holes, and the rest of the elements that make it up, which begins to contract, this would become a much hotter and denser place, and the structures would begin to break down. disarm. We would no longer have stars, planets and galaxies, but rather a kind of increasingly hot and dense fluid”, described Daniela Pérez, Conicet researcher at the IAR and first author of the study published in the scientific journal Physical Review D.
“We wonder if there is any kind of object capable of surviving that loss of structure, going through the rebound and emerging intact in the expansion phase we are in now. Our candidates were black holes, because they are regions of space-time disconnected from the rest of the universe, which are not made up of particles, atoms or electrons; they are just space-time”, explained the researcher.
Pérez stressed that this type of study has implications for modern cosmology, the branch of physics that studies the universe, since, among other things, they could allow us to understand why supermassive black holes – millions of solar masses – managed to gather so much mass in the period of time that takes the stage of cosmological expansion.
”The classic exact solutions of black holes do not take into account that they are embedded in the universe and, therefore, feel the dynamic changes that take place in it. Then we turn to solutions of more complex Einstein field equations, known as McVittie space-times, which do incorporate this characteristic”, said the researcher.
In the first model that the author and the authors explored, black holes cannot survive a contraction and rebound scenario, because the event horizon of these objects -the border or physical limit that defines them- disappears when it is associated with the horizon cosmological, that is, the observable limit of the cosmos.
”So we thought of even more realistic solutions and in the second study, which we carried out together with Dr. Gustavo Romero, instead of using the McVittie metric we used what is called the generalized McVittie metric, which is more complex mathematically and shows a better interaction of the event horizon of black holes with the dynamics of the universe”, he concluded in this regard.
With information from Telam