Researchers at the University of Florida have proposed a new method for detecting ultralight dark matter particles using astrometry, the precise measurement of celestial object positions and motions. This approach is based on the idea that ultralight dark matter particles produce measurable spacetime fluctuations that can be detected through precision measurements.
According to Dr. Sarunas Verner, one of the co-authors of the paper, previous searches for ultralight dark matter have relied heavily on pulsar timing arrays. However, their new method focuses solely on gravitational interactions, which could allow researchers to search for dark matter candidates decoupled from the Standard Model.
The proposed method relies on the fact that ultralight dark matter creates small spacetime fluctuations that affect the apparent positions of distant celestial objects, such as stars and quasars. These fluctuations cause classical aberration, resulting in subtle variations that require highly precise astrometric measurements.
Verner explained that these effects are extremely subtle, requiring measurements with precision better than 1 microarcsecond. The researchers showed that current and next-generation astrometric surveys like VLBI, Gaia, and THEIA could potentially detect these effects.
The new detection method has significant implications for the search for ultralight dark matter particles in the mass range below 10-22 electron volts. When combined with other datasets such as cosmic microwave background measurements and large-scale structure observations, precision astrometry could enhance our ability to detect or constrain these particles.
Verner noted that their approach is complementary to existing probes of ultralight dark matter and plans to extend this framework to investigate other sub-types of ultralight dark matter. The researchers are also exploring the application of similar principles to probe the nature of dark energy, potentially offering new insights into cosmic acceleration.
Source: https://phys.org/news/2025-04-astrophysicists-method-ultralight-dark.html