Recent research from the University of Geneva reveals that dark matter, the elusive substance thought to make up about 27% of the universe, behaves in ways similar to ordinary matter. This study, published in Nature Communications on November 16, 2025, examines how dark matter interacts with gravitational wells, providing insights into its fundamental properties.
The central goal of the research was to determine whether dark matter follows the same physical laws that govern visible matter. This has long been a crucial question in cosmology, as dark matter does not emit or reflect light, making it extremely challenging to study directly. The team, led by Camille Bonvin, an associate professor at UNIGE’s Faculty of Science, focused on comparing the velocities of galaxies with the depths of the gravitational wells they inhabit.
Researchers aimed to see if dark matter behaves predictably, akin to ordinary matter, as it moves through these cosmic gravity wells. According to Bonvin, if dark matter is influenced solely by gravity, galaxies — which are primarily composed of dark matter — should fall into these wells in a manner consistent with established physical principles, including Einstein’s general relativity and Euler’s equations.
By analyzing modern cosmological data, the researchers found that dark matter appears to move into gravitational wells similarly to ordinary matter. This suggests that it adheres to the same laws of physics, aligning with the predictions of Euler’s equations. However, the findings do not entirely eliminate the possibility of an undiscovered fifth force acting on dark matter.
The study’s first author, Nastassia Grimm, notes that while their conclusions support the idea that dark matter follows the same rules as ordinary matter, they cannot dismiss the existence of a subtle additional force. She indicated that if such a force exists, its strength must not exceed 7% of the gravitational force, as a stronger force would have likely been detected in their analyses.
As scientists continue to explore the complexities of dark matter, the next phase of research will focus on identifying whether any additional forces impact its behavior. Isaac Tutusaus, a co-author of the study and a researcher at the Institute of Cosmology and Gravitation, highlighted that upcoming experiments, such as the Large Synoptic Survey Telescope (LSST) and the Dark Energy Spectroscopic Instrument (DESI), could detect forces as weak as 2% of gravity. This could provide further insights into the behavior of dark matter.
The implications of this research extend beyond theoretical physics; understanding dark matter is crucial for unraveling the universe’s structure and evolution. With dark matter believed to be five times more abundant than ordinary matter, any new findings can significantly enhance our comprehension of cosmic phenomena.
In summary, the findings from the University of Geneva represent a significant advancement in our understanding of dark matter. As researchers continue to probe the mysteries of the cosmos, the prospect of discovering new forces or interactions remains an exciting frontier in modern physics.
