Researchers can easily study the matter that constitutes us humans, our planet, and other solar systems, but there is still no technology that can make dark matter visible to us. Researchers are convinced that dark matter is composed of a new type of particle that is not yet identified, but is known to have about five times the average mass density of regular matter in the universe. Research on dark matter in Sweden has mainly focused on measuring the particles’ characteristics indirectly, that is, by searching for traces of dark matter as it decays or annihilates - for example, by using models predicting that dark matter can emit signals in telescopes such as NASA’s Fermi satellite.

Dark matter can be detected in mines

The Milky Way contains much more dark matter than visible.
The Milky Way contains much more dark matter than visible.

Dark matter can also be detected directly by placing very sensitive cryogenic detectors into mines, which are protected from radiation, deep underground. This detection method enables researchers to test theories concerning dark matter that cannot be tested in any other way. One of the most successful ideas is to use detectors based on liquid xenon - a method that has made great strides in the past ten years.

Large research grant from the Knut and Alice Wallenberg Foundation

Professor Jan Conrad was recently awarded a SEK 29 million grant from the Knut and Alice Wallenberg Foundation for the study of dark matter particles in a laboratory environment.

The building of the XENON 1T experiment in Italy.
The building of the XENON 1T experiment in Italy.

In this project, researchers from the Department of Physics at Stockholm University will use the world’s most sensitive detector, which is currently being built in a tunnel under the Gran Sasso massif in the Apennine Mountains in Italy, to continue searching for traces of dark matter.

Demand for great computing power and advanced algorithms

“The challenge lies in reducing the noise from radioactive isotopes and cosmic radiation that might hide the very weak signal from dark matter. The extreme noise reduction required will demand great computing power and advanced algorithms, areas to which we in Sweden are in a good position to make a significant contribution”, says Jan Conrad.

Jan Conrad
Jan Conrad. Photo Eva Dalin

“Being able to use both methods to search for dark matter significantly increases the chances of discovery. If our paradigm is accurate, there is a clear possibility of a discovery in the near future.