Does the dark energy become weaker? New data support surprising discovery

Does the dark energy become weaker? New data support surprising discovery

fresh data support the discovery that the dark energy, the mysterious force that the galaxies drives apart, has subsided in the past 4.5 billion years.

The effect was cautiously In April last year reported, but the latest results that were presented on March 19 by Dark Energy Spectroscopic Instrument (DESI) Cooperation at a meeting of the American Physical Society in Anaheim, California, is based on three years of data recording, compared to one year for which in 2024 Results.

"Now I'm really aware of it," says Catherine Heymans, astronomer at the University of Edinburgh, Great Britain, and astronomer of the Kingdom of Scotland.

If the results are confirmed, this could force cosmologists to revise their “standard model” to the history of the universe. The model generally assumed that the dark energy is an inherent quality of the empty space that does not change over time - a "cosmological constant".

"The challenge was given to the physicists to explain this," says Heymans.

cosmic mapping

The desi telescope is located in Kitt Peak National Observatory near Tucson, Arizona. It uses 5,000 robot arms to focus on selected points where galaxies or quasare are in its field of vision. The fibers then provide light on sensitive spectrographs, which measure how strong each object is red -driven - this means to what extent its light waves have been stretched by the expansion of the space on their way to earth. Researchers can estimate the distance of an object based on its red shift in order to create a 3D card of the universe expansion.

In this card, the researchers then consider the density of the galaxies to identify variations that come from sound waves, which are called the baryonic acoustic oscillations (BAOS) and existed before stars began to form. These variations have a characteristic scale that began in the primordial universe at 150 kiloparsec (450,000 light years) and increases with cosmic expansion; They have now grown by a factor of 1,000 to 150 megaparsec, which makes them the largest known structures in the current universe.

By persecution of the developing size of the BAOS, researchers can reconstruct how the universe's expansion rate has changed in the course of the Äons. About 5 billion years ago, the expansion changed from a delay to an acceleration under the influence of dark energy. By last year, the cosmological data was in line with the fact that the dark energy is a cosmological constant - which meant that the universe should continue to expand with an increasingly faster rate.

But the results of the latest analysis of Desi indicate that cosmic expansion now accelerates less than in the past, which does not match the assumption that the dark energy is a cosmological constant. Instead, the data suggests that the energy density of the dark energy - the amount of dark energy per cubic meter space - is now about 10 % lower than 4.5 billion years.