Prof. Szymon Pustelny has been selected as a recipient of the Fulbright STEM Impact Award, under which he will carry out a six-week research project at Northwestern University in the United States. The project will be devoted to developing new methods for searching for dark matter – a mysterious component of the Universe which, despite constituting most of its mass, still eludes attempts at direct observation.
Dark matter plays a key role in cosmology – it is thanks to it that the Universe has taken on the structure observed today, containing planets, stars, and galaxies. Nevertheless, its nature remains one of the greatest mysteries of modern physics. Since experiments conducted so far have not produced conclusive results, scientists continue to develop new concepts regarding what dark matter is and how it might be detected.
Although all attempts to directly detect dark matter to date have failed, astronomical observations show that it interacts gravitationally with visible matter. For this reason, Prof. Szymon Pustelny has proposed a new search method based on gravitational measurements. The challenge in this case, however, is that despite its ubiquity, gravity is an exceedingly weak interaction. Therefore, attempting to use it to detect dark matter requires the most sensitive sensors known. To this end, the scientist has established a collaboration with the team of Prof. Andrew Geraci from Northwestern University – a world leader in optomechanics, a field that uses light to study the mechanical properties of systems. An example of the work carried out by the American team includes research on microscopic particles levitating in space under the influence of laser light. Precise control and monitoring of this light not only allow the particles to levitate, but also make it possible to register extremely weak forces acting on them. As a result, they can become tools for measuring subtle gravitational interactions whose source could be, for example, dark matter.
An important element of the project proposed by Prof. Szymon Pustelny is the use of optomechanical sensors to create a global network of detectors. Coordinated readouts from such sensors could help identify objects made of dark matter whose sizes would be comparable to that of the Earth or even larger. For years, the professor has been developing this type of approach within the international GNOME network, which enables the identification of weak signals appearing simultaneously in many independent laboratories. Detecting such simultaneous signals suggests the existence of a global disturbance affecting the sensors, while at the same time allowing the influence of local noise to be limited – thus increasing the sensitivity of the search. Connecting optomechanical sensors into a global network opens the way to a completely new approach to studying the problem of dark matter.
The research stay at Northwestern University constitutes the first step toward long-term international collaboration aimed at building a global network of ultra-sensitive gravitational detectors. Such infrastructure could in the future provide unique data on the nature of dark matter, but also contribute to the development of innovative measurement technologies – finding applications, for example, in the search for mineral deposits or in forecasting seismic shocks.
The Fulbright STEM Impact Award, administered by the Polish-American Fulbright Commission, is a program that enables individuals employed at Polish academic and research institutions to carry out independent research or research-and-teaching projects at host institutions in the United States – such as American universities, research institutes, government institutions, or non-governmental organizations. The fellowship is addressed to research and teaching staff at all career stages after obtaining a doctoral degree.
Fourteen applicants took part in the competition. Eight of them will carry out their research projects in the United States in the second semester of the 2025/26 academic year.
Text: Łukasz Wspaniały