When we look into the night sky, the galaxies of our Universe seem to clump together like foam on the surface of the ocean, creating amazing clumps and threads around inky voids.
However, to achieve such an amazing structure required eons and the action of gravity on the hot haze of particles released by the Big Bang.
Physicists at the University of Michigan, led by Nhat-Minh Nguyen, Dragan Khaterer and Yuewei Wen, set out to solve another mystery of the Universe and, perhaps, change our understanding of it.
Their research suggests a new adjustment to the model of the Universe, and it may help resolve a serious conflict in the data related to the expansion of the Universe.
Observations tell us that the Universe is expanding. The rate of this expansion is measured using the so-called Hubble constant (H0).
However, there is a small problem: different measurement methods give us different values of H0. For example, when studying exploding stars, we get an H0 value of about 74 kilometers per second per megaparsec. While studying the cosmic microwave background brings this value closer to 67 kilometers per second.
This may seem like a small difference, but it creates an insurmountable conflict in our understanding of the universe. This is where scientists turn their attention to “dark energy.”
“If gravity acts as an amplifier, increasing the perturbations of matter and promoting the formation of large-scale structure, then dark energy acts as a shock absorber, reducing these perturbations and slowing the growth of structure,” explains lead author of the study Nguyen.
To unravel this mystery, the researchers analyzed data on the growth of the large-scale structure of the Universe, including patterns in the distribution of galaxies and cosmic radiation. Their findings showed that the Universe is expanding more slowly than predicted by the current ACDM (Cosmological Dark Energy and Dark Matter) model.
“The difference in growth rates that we found becomes more pronounced as we get closer to today,” Nguyen emphasizes.
Although it is not yet clear what exactly is slowing the growth of the large-scale structure of the Universe, this research raises important questions about how our Universe evolves and whether the current understanding of the model may be flawed.
It took billions of years for the universe to reach its current form, and it may take us some more time to finally unravel the mystery of its origins and the expansion that is taking place.
