A groundbreaking survey of the universe is uncovering new insights into the enigmatic force known as dark energy. Surprisingly, the data suggests that dark energy, which is believed to have a constant density, may actually change as the universe evolves.
Dark energy, an invisible force responsible for the universe’s accelerating expansion, remains a mystery despite being the dominant component of the universe. To unravel this mystery, the Dark Energy Spectroscopic Instrument (DESI) has created the most extensive 3-D map of the universe to date. This achievement was reported in 10 papers published on the DESI website and presented at a meeting of the American Physical Society in Sacramento, Calif. By analyzing the distribution of galaxies and other celestial objects on the map, scientists can trace the history of the universe’s expansion.
While the data align with the standard model of the universe, they also open up the possibility that the equation of state of dark energy, which describes its pressure in relation to density, may vary over time. This potential discovery could revolutionize our understanding of the universe’s history.
The study is based on the first year of data from the project, which mapped the locations of 6.4 million galaxies and quasars. This map enables scientists to estimate the rate of the universe’s expansion by using sound waves from the early universe as a size reference. These waves created density patterns in the universe, known as baryon acoustic oscillations, which persist as galaxies form. The resulting preferred distance between galaxies acts as a ruler that is stretched by the universe’s expansion. Measuring the size of this ruler across different cosmic eras provides insights into the universe’s expansion.
2024-04-04 10:00:00
Source from www.sciencenews.org