American scientists, using mathematical tools, described the inhomogeneities of the cosmic microwave background radiation that arose immediately after the origin of the Universe. The authors believe that their results confirm the correctness of the Big Bounce hypothesis, according to which the emergence of our universe was the result of the disintegration of some "previous" universe. The results are published in the journal Physical Review Letters.
While Einstein's theory of general relativity explains a wide range of astrophysical and cosmological phenomena, some properties of the universe remain a mystery. In particular, it cannot explain the uneven distribution of galaxies and dark matter in space.
Since the 1980s, Penn State University staff have been developing a cosmological paradigm based on the concept of loop quantum gravity. This paradigm, called loop quantum cosmology, describes all modern large structures in the Universe as quantum fluctuations of space-time that took place at the birth of the world.
According to the generally accepted theory of the Big Bang, it all started with a singularity - a state in which all matter and energy were compressed into one point. Then, in the first fraction of a second, during a period called inflation, the cosmos swelled to enormous proportions. But the Big Bang theory does not explain what happened before the singularity, so this state cannot be described in terms of the laws of physics and mathematics.
Scientists at Pennsylvania State University hold the alternative Big Bounce hypothesis, according to which the current expanding universe arose from the supercompressed mass of the universe of the previous phase. To describe this state, they use a universal mathematical apparatus that combines quantum mechanics and the theory of relativity.
The authors trace the origin of the structure of the Universe to the smallest inhomogeneities recorded against the background of the microwave background cosmic relic radiation, which was emitted when the Universe was only 380 thousand years old.
But this radiation itself has three mysterious anomalies that are difficult to explain using classical physics. These deviations are so serious that many physicists began to talk about a crisis in cosmology.
In a new study, scientists argue that, from a loop quantum cosmology perspective, describing inflation eliminates two major anomalies in the CMB distribution.
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“Using quantum loop cosmology, we naturally resolved two of these anomalies, avoiding a potential crisis,” co-author Donghui Jeong, associate professor in the Department of Astronomy and Astrophysics, said in a university press release. "The presence of these anomalies suggests that we live in an exceptional universe."
The authors believe that the inhomogeneities of the CMB are the result of inevitable quantum fluctuations in the early Universe. During the accelerated phase of expansion - inflation - these initially tiny fluctuations were stretched by gravity, reflected in the observed irregularities.
"The standard inflationary paradigm, based on general relativity, views spacetime as a smooth continuum," said the first author of the paper, Professor Abhay Ashtekar, director of the Pennsylvania Institute of Gravity and Space. - The fabric of the shirt also looks like a two-dimensional surface, but upon closer inspection you can see that it is woven from densely packed one-dimensional threads. In the same way, quantum threads are woven into the fabric of space-time. Given these strands, loop quantum cosmology allows us to go beyond the continuum described by general relativity."
Scientists hope that new satellite missions such as LiteBIRD and Cosmic Origins Explorer, aimed at detecting traces of primary gravitational waves against the background of the CMB, will confirm their findings.