New method helps measure cosmological distances more accurately

A team of researchers from several Chinese universities and the University of Córdoba conducted a complex statistical analysis of about one million galaxies, and was able to publish the findings in the journal Nature Astronomy. Over his two years, they worked on a project aimed at enabling cosmological distances to be determined to a new high level of accuracy. In this study, we developed a new method to detect so-called baryon acoustic oscillations (BAOs). First proven in 2005, these waves are among the few traces of the Big Bang that can still be detected in the universe. Spread over the first 380,000 years of the universe’s birth, it propagates like sound waves through very hot matter and behaves like a liquid in the same way that you throw a stone into a pond. The universe then expanded and eventually cooled enough to freeze these waves. The interesting thing about these oscillations, which bear witness to nearly the entire history of the universe, is that their exact durations are known, so they are now very useful for measuring cosmological distances based on intergalactic distances. . Therefore, being able to detect them and determine their size is paramount to accurately mapping the universe to very distant points.

“The results of this work allow us to detect these waves in a new and independent way. Combining the two, we can more accurately determine distances in space,” said the Department of Physics. Antonio J. Cuesta, an investigator of the study and the only Spanish author of the study, explained: A new method: looking for orientation anomalies in galaxies, this new study pays particular attention to two very different factors in his work, the ellipticity of galaxies and the density of their surroundings, and uses statistical methods to find the approximation of one million of them. galaxy database was analyzed. Under the influence of gravity, galaxies usually expand to locations where there are more other galaxies in relation to their orientation. However, there are certain places in space where this effect is not as strong. “Statistics show that at points where galaxies are not oriented, baryonic acoustic oscillations occur because these waves also act as points of gravitational attraction,” Antonio J.・Mr. Cuesta explained. Look far, look into the past “The first practical application this research might have is to pinpoint where galaxies are and how far they are from Earth, but in a way, I We are also looking into the past,” the researchers explained. This new approach to acoustic baryon oscillations holds the key to answering some big questions about the universe and opens new doors in the world of astronomy. Determination of cosmological distance provides new clues to the history of the expansion of the universe and helps us understand its composition in terms of its most elusive and enigmatic components, dark matter and energy.

Source: Kun DOI: 10.1038/s41550-023-02035-4