Recent research conducted by scientists at the University of Geneva has revealed that dark matter may behave more like ordinary matter than previously thought. The study, published on November 16, 2025, in the journal Nature Communications, examines the movement of galaxies within cosmic gravity wells, suggesting that dark matter adheres to the same fundamental physical laws that govern visible matter.
Dark matter, an elusive substance that neither emits nor reflects light, has long posed challenges for researchers seeking to understand its nature. The new findings indicate that dark matter appears to sink into gravitational wells in a manner similar to ordinary matter. This insight could significantly enhance our understanding of the universe, given that dark matter is believed to be five times more abundant than the visible matter we can observe.
To investigate these behaviors, the research team analyzed the velocities of galaxies in relation to the depth of gravitational wells. Massive cosmic objects distort the fabric of space, creating these wells, into which both ordinary matter and dark matter fall. The study aimed to establish whether dark matter experiences the same gravitational influences as the matter we can see.
Camille Bonvin, an associate professor in the Department of Theoretical Physics at UNIGE and a co-author of the study, explained the importance of their approach. “If dark matter is not subject to a fifth force, then galaxies—which are mostly made of dark matter—will fall into these wells like ordinary matter, governed solely by gravity,” she stated. “If a fifth force acts on dark matter, it will influence the motion of galaxies differently.”
The researchers found that dark matter’s movement aligns with Euler’s equations, which describe the behavior of fluids in motion. This consistency suggests that, at least within the parameters studied, dark matter follows the same physical principles as ordinary matter. However, the researchers noted that the possibility of an undiscovered fifth force cannot be entirely dismissed.
According to Nastassia Grimm, the study’s lead author and a former postdoctoral researcher at UNIGE, “If such a fifth force exists, it cannot exceed 7% of the strength of gravity; otherwise, it would have already manifested in our analyses.” This finding narrows the potential characteristics of any additional forces that may interact with dark matter.
Looking ahead, scientists aim to further investigate the nature of dark matter and the possibility of subtle forces affecting it. Isaac Tutusaus, a researcher associated with ICE-CSIC and the University of Toulouse, emphasized the importance of future experiments. “Upcoming data from projects like LSST and DESI will be sensitive to forces as weak as 2% of gravity, which should allow us to gain deeper insights into dark matter’s behavior,” he concluded.
These early findings mark a significant step in the ongoing quest to decode the mysteries of dark matter, a substance that continues to shape our understanding of the universe. As researchers refine their methodologies and access new data, the potential for groundbreaking discoveries remains high.
