The authors believe that to explain the observation results, it is sufficient to formulate a mathematical model more accurately.
The mysterious dark energy, which should account for a significant part of the universe, does not actually exist at all. This conclusion was reached by the American-Hungarian group of cosmologists, who published their vision of the problem in the monthly journal of the Royal Astronomical Society.
Our Universe was formed as a result of the Big Bang 13.8 billion years ago and has been expanding since then. The key proof of expansion is Hubble's law: the speed of "recession" of galaxies is the greater, the greater the distance to them. Or, to put it a little more scientifically, the redshift of a galaxy is proportional to the distance to it. The law was formulated back in the 1920s on the basis of observations, you cannot argue with it.
In the second half of the 20th century, astronomers, in search of explanations for the observed motion of celestial bodies, proposed the concept of "dark matter" - practically not interacting with other elements of the universe and therefore imperceptible. The last 25 years of observations of supernova explosions of type Ia, the luminosity of which is recognized as a reference, led scientists to the conclusion that their redshift does not correspond to what should be observed according to Hubble's law. The universe turned out to be not just expanding, but expanding with acceleration. To explain this phenomenon, the term "dark energy" was coined. According to modern concepts, the share of dark energy in the Universe is about 68%, the share of dark matter is 27%, and the share of ordinary matter we are accustomed to is a little less than 5%.
In the new work, the researchers led by graduate student Gábor Rácz from Budapest University. Laurent Eotvos, in connection with the available facts, offer a new explanation. They argue that the currently accepted cosmological models ignore the structure of matter, ascribing a uniform density to it.
A small animation showing the expansion of the Universe in terms of three cosmological models. Top right to left shows the currently accepted model (red) with dark energy, the Avera collaboration model (described in the material, blue) and the Einstein-de Sitter model (green), also without dark energy. Below is the increase in the scale factor of the three models.
Using computer simulations of the effect of gravity on the distribution of dark matter particles, scientists were able to reconstruct the evolution of the universe, including the formation of large-scale structures. Unlike conventional simulations, in which the universe expands smoothly, taking into account cosmic structures has led to the construction of a model in which different parts of space expand at different rates, although on average the expansion acceleration is consistent with observational data.
“The equations of Einstein's general theory of relativity describing the expansion of the Universe are so complex mathematically that for a hundred years no solutions have been proposed that take into account the influence of cosmic structures. From supernova observations, we know for sure that the universe is expanding with acceleration, but at the same time we rely on rough approximations in Einstein's equations, which can cause serious side effects, such as the appearance of dark energy to match the observations, explains co-author of the article Dr. Laszlo Dobos (László Dobos). - The general theory of relativity is the foundation for understanding the path of the development of the Universe. We do not question it, we doubt the approximate solutions. Our conclusions are based on a mathematical hypothesis that considers differential expansion of space in accordance with general relativity, and they show how the formation of complex structures of matter affects this expansion. These questions were not popular before, but, taking them into account, it is possible to explain the acceleration in the expansion of the Universe without attracting dark energy."