Photo: ESA / Hubble / Globallookpress.com
An international team of astronomers came to the conclusion that the density of dark energy where the universe expands with acceleration should increase over time. Article scientists published in the journal Nature Astronomy.
Called dark energy hypothetical form of energy which is observed accelerated expansion. According to estimates, it should reach about 70 percent of the mass of the Universe. According to one explanation, any volume of space has a certain density of dark energy, called the cosmological constant. Since the volume of the Universe increases, and the amount of dark energy. The cosmological constant is very small, and no theoretical model does not predict its exact value, which is one of the unsolved problems of modern physics.
At the moment, the cosmological model Lambda-CDM (ΛCDM) is the most accurate description of the evolution and large-scale structure of the Universe. It mathematically describes the evolution of a flat Universe after the Big Bang and having a non-zero positive cosmological constant (lambda). The model explains the observed structure of the CMB (cosmic microwave background), the distribution of galaxies in the Universe, the abundance of hydrogen and other light atoms, as well as the rate of expansion of the vacuum.
Almost all observations correspond to ΛCDM, but the model is poorly tested at great distances, between the most distant type Ia supernovas and the surface of last scattering (cosmic microwave background) located at a distance of about 46 billion light years (the distance does not coincide with the age of the Universe at 13.8 billion light years due to accelerated expansion). Scientists have conducted a new measurement of the speed of expansion by building a Hubble diagram (the relationship between apparent brightness and red shift) for more than a thousand quasars.
Astronomers have discovered that the ratio of the module of distance and red shift (red shift to determine the distance to distant space object) corresponds to the model of the distance which the light passed for 9.1 billion years (redshift less than 1.4). However, at higher redshift, deviations from ΛCDM, which indicate that with the age of the Universe the density of dark energy should increase.
Video, photo All from Russia.