Study Finds Dark Matter Behaves Like Ordinary Matter, Suggests Similar Forces
A recent study conducted by researchers from the University of Geneva has provided new insights into the nature of dark matter, suggesting that it behaves similarly to ordinary matter under the influence of gravity. The findings, published in the journal Nature Communications, challenge previous notions that dark matter could be governed by unknown forces.
The research team aimed to explore whether dark matter, which is believed to constitute approximately 85% of the universe’s total mass, follows the same gravitational laws as visible matter. Their investigation focused on how dark matter interacts with gravitational wells created by massive celestial bodies. In contrast to ordinary matter, which includes planets and stars, dark matter is invisible and does not emit light, making its behavior a complex subject of study.
Study Methodology and Findings
To assess the behavior of dark matter, the team compared the velocities of galaxies, primarily composed of dark matter, with the depth of gravitational wells. According to Camille Bonvin, an associate professor at UNIGE, “If dark matter is not subject to a fifth force, then galaxies will fall into these wells like ordinary matter, governed solely by gravity.” Conversely, if a fifth force exists, it would influence how galaxies move, altering their trajectories.
The researchers utilized cosmological data to analyze the motion of galaxies and their interaction with gravitational wells. Their findings indicated that dark matter falls into these wells similarly to ordinary matter, adhering to Euler’s equations. This observation suggests that the established laws of physics apply to dark matter, at least in this context.
While the study affirms that dark matter behaves like ordinary matter, it does not entirely dismiss the possibility of a fifth force acting upon it. As Nastassia Grimm, the lead author of the study, noted, “If such a fifth force exists, it cannot exceed 7% of the strength of gravity; otherwise, it would have manifested in our analyses.”
Implications for Future Research
These findings represent a significant advancement in the understanding of dark matter and open avenues for further exploration. Researchers are now tasked with determining whether a fifth force influences dark matter’s behavior. Upcoming data from advanced experiments, such as the Legacy Survey of Space and Time (LSST) and the Dark Energy Spectroscopic Instrument (DESI), are expected to be capable of detecting forces as weak as 2% of gravity. Such data could provide deeper insights into the enigmatic properties of dark matter.
Isaac Tutusaus, a co-author of the study and researcher at the Institute of Cosmology and Gravitation, emphasized the potential of these new experiments to expand our understanding of dark matter’s behavior. “They should therefore allow us to learn even more about the behavior of dark matter,” he concluded.
The results of this study mark a pivotal step in the ongoing quest to unravel the mysteries of dark matter, which remains one of the most elusive components of our universe. As scientists continue to explore its properties, the implications of these findings may reshape our understanding of the cosmos.
Further information can be found in the article “Comparing the motion of dark matter and standard model particles on cosmological scales,” published in Nature Communications in March 2025.
