Researchers have used simulations to investigate the cosmic web, the large-scale galaxies pattern that exists throughout the universe. By treating the distribution of galaxies as a collection of points, they have quantified the relative disorder of the universe and gained an insight into its fundamental structure.
The universe is dotted with galaxies that, on large scales, exhibit a filamentary pattern, known as the cosmic web. In some ways, this heterogeneous distribution of cosmic material is like blueberries in a muffin, where material clusters in certain regions but may be absent in others.
Researchers have begun to investigate the universe's heterogeneous structure by treating galaxies as a collection of points rather than as a continuous distribution, in addition to enabling the application of mathematical knowledge for materials science to better understand the universe's fundamental structure.
The Sloan Digital Sky Survey shows off the largest structures in the universe, including NASA/University of Chicago and the Adler Planetarium and Astronomy Museum.
"What we discovered was that the distribution of galaxies in the universe is quite different from the physical properties of conventional materials, having its own unique characteristic," according to Oliver Philcox, a co-author of the study.
Salvatore Torquato, a frequent member and visitor at Princeton University's chemistry and physics departments, and Oliver Philcox, a visiting Ph.D. student at the Institute from September 2020 to August 2022, are both members of the Simons Society of Fellows.
This 3D photograph shows the largest structures in the universe, beginning with data from the Sloan Digital Sky Survey, and expanding to reveal data from the Adler Planetarium and Astronomy Museum.
Each of the 1,000 experiments consisted of a billion dark matter "particles," which, as a result of gravitational evolution, serve as a proxy for galaxies.
One of the main findings of the research is the fact that two galaxies are topologically connected to one another via the pair-connectedness function, thus indicating that on the largest scales (up to several hundred megaparsecs), the universe approaches hyperuniformity, while on smaller scales (up to 10 megaparsecs) it becomes almost antihyperuniform and strongly inhomogeneous.
Dark matter halos are indicated by points, and their related large-scale topological structures are indicated by colors in a section of the universe (black and white).
"The perception of order and disorder is largely dependent on scale," said Torquato. "The pointillist technique used in Georges Seurat's painting A Sunday on La Grande Jatte (see image below) produces a similar visual effect; the work appears disordered when viewed up-close and highly ordered from afar. "In terms of the universe, the degree of order and disorder is more subtle, as with a Rorschach inkblot test that can be interpreted in infinite numbers of
Georges Seurat's poem "A Sunday on La Grande Jatte"
The researchers developed a consistent and objective framework for assessing order, as well as a number of other dynamical and physical systems, using statistical tools.
This interdisciplinary research, which combines cosmology and condensed matter physics, has future applications for both disciplines. Among these are cosmic voids and the ionized hydrogen bubbles that formed during the reionization phase of the universe. Moreover, the findings may provide insight into other material systems on Earth.
Oliver H. E. Philcox and Salvatore Torquato's reference: "Disordered Heterogeneous Universe: Galaxy Distribution and Clustering across Length Scales"