New research suggests that the age of the universe may be younger than previously predicted by standard cosmological models.
A team of scientists led by Prof. GUO Qi from the National Astronomical Observatories of the Chinese Academy of Sciences analyzed the motions of satellite galaxies around massive galaxy groups using data from the Sloan Digital Sky Survey (SDSS) .
In standard cosmological models, the formation of cosmological structures begins with the emergence of small structures, which then undergo hierarchical merging, leading to the formation of larger systems. As the universe ages, massive galaxy groups and clusters tend to increase in mass and reach a more dynamically relaxed state .
The researchers focused on the movement of satellite pairs positioned on the opposite side of massive galaxy groups. They analyzed the velocity offsets of these pairs from the central galaxy along the line of sight. The team discovered a notable excess of pairs exhibiting correlated velocity offsets compared to pairs displaying anti-correlated velocity offsets. This excess suggests the presence of recently accreted or infalling satellite galaxies.
The study’s findings present a challenge to the current cosmological model and may provide valuable insights into the Hubble tension problem. The research paper was published in Nature Astronomy.
Interestingly, this excess was also found in cosmological simulations, but the magnitude of the effect was considerably lower than in the observations. This significant discrepancy between the observations and simulations implies that massive galaxy groups in the real universe are younger than expected .
The age of massive galaxy groups is closely related to the age of the universe itself. Therefore, these findings suggest a younger universe compared to previous estimates derived from the cosmic microwave background (CMB) by the Planck Collaboration.