The results of a new study by American astronomers, published in the journal Astrophysical Journal Letters, indicate that the universe is expanding about 10 percent faster than expected on the basis of the observations made by the space telescope “Planck”, which may indicate the need for new physics, which will allow scientists to better understand the cosmos and what is happening in events, reports Space.com. A Preprint of the work can be freely available in online repositories of scientific articles.
The probability that this discrepancy is a mere coincidence, declined from one three-thousandth to one hundred-thousandth, the researchers note.
“This discrepancy has reached the point where to call it an accident anymore,” says the head of research Adam Riess, Professor of physics and astronomy at Johns Hopkins University in Baltimore (USA).
“It’s not what we were expecting,” Riess adds that in 2011 (together with other physicists by Brian Schmidt and Saul Perlmutter) received the Nobel prize in physics for proof of the accelerated expansion of the Universe and the development of precise methods of measuring distances.
Scientists are still unable to understand what increases the rate of expansion of the Universe, but many astronomers think the culprit of this is the mysterious repulsive force called dark energy.
This illustration shows the three basic steps that astronomers use to calculate the speed of expansion of the Universe in time. This value is called the Hubble Constant. All steps include the build steps of “space remote of the ladder”, starting with measuring accurate distances to nearby galaxies and then moving to the galaxies farther and farther away. This “ladder” is a series of measurements of different types of astronomical objects from their luminosity indicators that can be used to calculate distances
In the new study, Riess, along with colleagues used data from the space telescope “Hubble” that contains information about observations of 70 Cepheids (stars with variable brightness) in the Large Magellanic Cloud, a galaxy neighboring our Milky Way. For astronomers Cepheids are a kind of beacons, due to the dependence of the period—luminosity of Cepheids are used as standards of luminosity in determining distances to remote objects.
Another “reference point” for computing the expansion rate of the Universe there may be type Ia supernovas whose light is stretched as the space that it overcomes expanding. However, the main problem is determining accurate distances to these stars. The analysis and observation for these stars allowed Riess, Schmidt and Permuter to receive the Nobel prize.
RISS team also included in their calculations, obtained in the course of the project “Araucaria” in which scientists from the U.S., Europe and Chile, conducted monitoring of binary star systems in the galaxy the Large Magellanic Cloud, noting that “Eclipse” stars that arose when one star passed in front of its neighbor. This work has provided for Riess and his colleagues additional information about the distances to stars, giving scientists a help in understanding the internal brightness of the Cepheids.
Armed with the data, the researchers used them to calculate the current speed of expansion of the Universe — values, which is called the Hubble Constant. Its name it received in honor of the famous American astronomer Edwin Hubble in the 20-ies of the last century. In the end, the researchers received a new value of the Hubble constant in 74,03 kilometers per second per megaparsec (1 megaparsec is approximately equal to about 3.26 million light years) that the more constants are derived from observations of the CMB and is 67 kilometers per second per megaparsec. This means that the speed of removal of galaxies from us is increased by nearly 74 kilometers per second, not 67, as it was considered before. The catch is that the previous value is taken into account in all our models that describe and the age of the Universe and its composition, as well as in the fundamental laws of physics.
According to the team RISSA, the maximum error in their calculation may be only 1.9 percent – the lowest at the moment. For example, in studies of 2001, the accuracy of calculations is approximately 10 percent and the data for 2009 mentioned on the error of 5 percent.
New estimates of the rate of expansion of the Universe strongly contradicts the value of the constant of Hubble, from the telescope “Planck” European space Agency, which conducted the study of cosmic background radiation left after Big Bang, which according to the most popular scientific opinion, gave birth to our Universe about 13,82 billion years ago.
“It’s not just two uncoordinated experiment. We measure something fundamentally different. In the first case we are talking about measuring how fast the universe is expanding visible today, and in the second we are talking about predictions based on physics of the early Universe and data on how fast it should expand. If these values do not match, there is a very high probability that we’re missing something in the cosmological model, which connects two eras,” concludes RISS.