The Universe’s structure is thought to have developed from tiny quantum fluctuations during its early inflation. These fluctuations created density variations that grew into large cosmic structures through gravitational instability.
In the early stages, the growth of these structures is linked to the motion of matter, as denser areas attract and accelerate surrounding material. By studying galaxy redshifts and distances, scientists can deduce the underlying density and velocity fields in the Universe.
A team of international researchers has taken a significant step forward in understanding the vast structure of the Universe, identifying key gravitational regions known as “basins of attraction.”
For this study, scientists assumed the lambda cold dark matter standard model of cosmology, which suggests that the Universe’s large-scale structure emerged from quantum fluctuations during the early stages of cosmic inflation. These tiny fluctuations in density grew over time, leading to the formation of galaxies and clusters we see today. As these density variations increased, they pulled in nearby matter, creating “basins of attraction” areas where gravity is stronger.
Using the latest Cosmicflows-4 (CF4) compilation data, the team applied a Hamiltonian Monte Carlo algorithm to map the Universe’s large-scale structure up to about a billion light-years away. This approach enabled them to assess the gravitational areas in the Universe, pinpointing the critical basins of attraction that influence how galaxies move.
Previous catalogs suggested that the Milky Way Galaxy is part of the Laniakea Supercluster. However, the new CF4 data indicates that Laniakea may be part of the larger Shapley basin of attraction, which covers an even bigger area of the local Universe.
Among the newly identified regions, the Sloan Great Wall is the largest basin of attraction, with a volume of about half a billion cubic light-years, more than double the size of the previously largest Shapley basin.
These findings offer fresh insights into the gravitational landscape of the local Universe and enhance our understanding of how galaxies and cosmic structures evolve and interact over time.
This study deepens our understanding of the Universe’s intricate gravitational dynamics and the forces that have shaped its structure. Identifying these basins of attraction marks a significant advancement in cosmology, likely changing how we understand cosmic flows and large-scale structures in the Universe.
By mapping out the basins of attraction—regions where gravity pulls galaxies and matter—the study reveals how massive cosmic structures influence the movement and formation of galaxies over time.
Journal Reference:
- Valade, A., Libeskind, N.I., Pomarède, D. et al. Identification of basins of attraction in the local Universe. Nat Astron (2024). DOI: 10.1038/s41550-024-02370-0
