Scientists Uncover Dark Matter’s Familiar Behavior in New Study

Scientists have made significant strides in understanding dark matter, revealing that it behaves similarly to ordinary matter in a recent study. Conducted by researchers from the University of Geneva and published in Nature Communications, the findings suggest dark matter follows familiar physical laws, although the possibility of an undiscovered force still exists.

Dark matter, an invisible form of matter that neither emits nor reflects light, has long puzzled scientists. The research team aimed to determine whether dark matter interacts with the same fundamental forces that affect ordinary matter, such as gravity, electromagnetism, and the strong and weak forces within atoms. Their study focuses on how galaxies move through cosmic gravitational wells, which are regions of space distorted by massive objects.

To investigate this, the researchers compared the velocities of galaxies across the universe with the depth of gravitational wells. They sought to establish whether dark matter behaves in the same predictable way as ordinary matter. According to Camille Bonvin, an associate professor in the Department of Theoretical Physics at UNIGE and a co-author of the study, “If dark matter is not subject to a fifth force, then galaxies—mostly made of dark matter—will fall into these wells like ordinary matter, governed solely by gravity.”

The findings indicate that dark matter indeed follows Euler’s equations, which describe the motion of fluids and solids. This suggests that dark matter moves into gravitational wells similarly to how ordinary matter does. Yet, Nastassia Grimm, the study’s first author and a former postdoctoral researcher at UNIGE, cautions that this does not entirely rule out the presence of an unknown force. “If such a fifth force exists, it cannot exceed 7% of the strength of gravity—otherwise, it would have already appeared in our analyses,” she stated.

Looking ahead, the research team aims to refine their understanding of dark matter further. The next goal is to determine if this subtle fifth force genuinely influences dark matter’s behavior. According to Isaac Tutusaus, a researcher at ICE-CSIC and co-author of the study, “Upcoming data from the newest experiments, such as LSST and DESI, will be sensitive to forces as weak as 2% of gravity, allowing us to learn even more about dark matter.”

These developments mark an important step in cosmology and could reshape our understanding of the universe. As dark matter is believed to make up about five times more of the universe than ordinary matter, every new insight sheds light on its role in the cosmos. The ongoing research into dark matter promises to unveil more about the fundamental workings of our universe, bringing scientists closer to solving one of its greatest mysteries.