A team of researchers led by the University of Southern California has developed a series of supercomputer-simulated twins of our Milky Way galaxy to delve into the mysteries of dark matter, the invisible substance that makes up a significant portion of the universe.

The project, named COZMIC, short for Cosmological Zoom-in Simulations with Initial Conditions beyond Cold Dark Matter, was spearheaded by cosmologist Vera Gluscevic, associate professor at USC Dornsife College of Letters, Arts and Sciences; Ethan Nadler, assistant professor at University of California, San Diego; and Andrew Benson, staff scientist at Carnegie Observatories.

The team's research has been published in The Astrophysical Journal, detailing the development of COZMIC and its implications for understanding dark matter and its role in the universe.

The Significance of Dark Matter

Dark matter, constituting about 85% of all matter in the universe, is crucial in understanding the formation and evolution of galaxies. Its existence has been known for decades, but its interactions with normal matter and its effects on the universe have been challenging to study.

Unlike normal matter, dark matter does not emit light or energy, making it difficult to detect. However, its influence on the motions and structures of galaxies provides clues to its nature and behavior.

Through the COZMIC simulations, the research team introduced new physics to study the properties and interactions of dark matter particles, enabling a deeper understanding of how dark matter affects the formation and evolution of galaxies.

Different Dark Matter Scenarios

The team explored various dark matter behavior scenarios in their simulations, including:

• Billiard-ball model: Dark matter particles collide with protons, smoothing out small-scale structures and eliminating satellite galaxies.
• Mixed-sector model: A hybrid scenario where some dark matter particles interact with normal matter while others do not.
• Self-interacting model: Dark matter interacts with itself, modifying galaxy formation over cosmic history.

By incorporating new physics into the simulations, the team aimed to create galaxies that exhibit the effects of interactions between dark matter and normal matter.

A New Era for Dark Matter Research

The COZMIC project represents a significant advancement in dark matter research, offering insights into the nature and behavior of this mysterious substance. By comparing their simulated galaxies to real telescope images, the team hopes to uncover more about the fundamental properties of dark matter.

Future plans involve testing the predictions from the simulations with telescope data to identify signatures of dark matter behavior in actual galaxies, bringing scientists closer to unraveling the mysteries of dark matter and its impact on the cosmos.