Russian and South Korean physicists have comprehensively analyzed three popular cosmological theories linking the super-fast expansion of the Universe in the first moments of its existence with various quantum processes, and have discovered evidence that only one of them is compatible with observational data. This was reported by the Center for Scientific Communication of MIPT.
The models we considered are minimal modifications of the general theory of relativity, which makes them the simplest natural candidates for the role of the true theory of cosmic inflation. We concluded that one model agrees well with observations for some parameter values, while the remaining two need modification
Scientists from MIPT, the Joint Institute for Nuclear Research, and the South Korean Institute for Basic Science came to this conclusion by analyzing possible scenarios of whether various manifestations of quantum mechanics can explain why the boundaries of the Universe expanded significantly faster than the speed of light in the first moments of its existence. This scenario, the so-called cosmological "inflation" of the Universe, is now not questioned by most physicists. However, the mechanisms of this super-fast expansion, as well as the reasons for its beginning and end, continue to be debated among scientists.
Russian and South Korean physicists have tested the correctness of three popular interpretations of this idea, claiming to be the true theory of cosmic inflation. To do this, the scientists studied data on the large-scale structure of the universe, collected using the WMAP, Planck, and Antarctic BICEP probes, and compared them with the results of calculations performed on the basis of computer models of the expanding Universe, built according to these three concepts.
This comparison showed that only one of the three theories corresponded to the real observational data. Within the framework of this theory, the super-fast expansion of the Universe is associated with the presence in it of a certain all-pervading field with a non-zero mass, which weakly interacted with gravity. The results of calculations of the other two models seriously diverge from the measurements of orbital and ground-based observatories, which narrows the number of quantum theories explaining the expansion of the early Universe, the scientists summarized.