Unusual discrepancies in the rate of expansion of the Universe in the first epochs of its life and today may indicate the existence of another type of bosons and the "fifth force of nature." This is the conclusion reached by cosmologists who published an article in the arXiv.org electronic library.
Back in 1929, the famous astronomer Edwin Hubble proved that our Universe does not stand still, but gradually expands, observing the movement of galaxies far from us. At the end of the 20th century, astrophysicists discovered, observing type I supernovae, that it was not expanding at a constant speed, but with acceleration.
The reason for this, according to scientists today, is "dark energy" - a mysterious substance that makes space-time stretch faster and faster.
In June 2016, Nobel laureate Adam Reiss and colleagues who discovered this phenomenon calculated the exact rate of expansion of the universe today using variable Cepheid stars in nearby galaxies, the distance to which can be calculated with ultra-high precision.
This refinement gave an extremely unexpected result - it turned out that two galaxies, separated by a distance of about 3 million light years, scatter at a speed of about 73 kilometers per second.
Such a figure is noticeably higher than the data obtained with the WMAP and Planck orbital telescopes show - 69 kilometers per second, and it cannot be explained using our ideas about the nature of dark energy and the mechanism of the birth of the Universe.
These discrepancies have prompted cosmologists to ponder possible explanations for this oddity. On the one hand, it is quite possible that the measurements by Planck or Riesz and his colleagues simply contain errors. On the other hand, it is also permissible that a third "dark" substance, different from dark matter and energy, could exist in the early Universe, as well as the fact that the latter could be unstable and gradually decay.
Dan Hooper, a renowned American cosmologist from the University of Chicago, and his colleagues "calculated" the properties of a possible candidate for the role of "third" substance, studying various "extended" versions of the Standard Model of physics, minimally outside its scope.
Promotional video:
The fact is that scientists have long suspected, relying not on several inexplicable anomalies in the properties and behavior of some elementary particles, that their interactions are conducted not only by photons and three carriers of strong and weak nuclear interactions, but also by the fifth type of such particles, the so-called gauge bosons …
For example, a few years ago, Hungarian physicists already announced the discovery of the "fifth force of nature" and the associated ultralight boson with a mass of about 20 MeV, which is about 50 times less than the weight of a proton or neutron.
Calculating the properties of a particle with a similar mass and properties, interacting with muons, tau particles and some types of neutrinos, Hooper and his colleagues found that these bosons will affect the behavior of the entire Universe as a whole in the first moments of its life in an extremely unusual way.
Based on data on the behavior of neutrinos collected during observations of a supernova explosion in 1987 in a neighboring galaxy, cosmologists have found that the decay of a large number of these bosons will heat up elusive "ghost" particles and prevent them from separating from the rest of the primary matter of the Universe.
This, in turn, will affect the expansion rate of the Universe, temporarily slowing it down while ultralight bosons are still present in the "soup" of the primordial matter of the universe and interact with neutrinos. As the calculations of Hooper and his colleagues show, the force of this inhibition will be exactly the same as indicated by the discrepancies in the measurements of Planck and Adam Riesz.
Verification of this theory, according to cosmologists, will become possible in the near future, when the CMB-S4 observatory at the Earth's south pole, designed to study the microwave "echo" of the Big Bang, begins its work. She, as the researchers conclude, will have sufficient sensitivity to search for disturbances generated by the decays of these ultralight bosons.
