Observational cosmology

The observational cosmology group is involved in the preparations for the European Space Agency’s Euclid mission.

Euclid is the wide-angle space telescope of the European Space Agency (ESA), which will map the three-dimensional structure of the observable universe. The primary goal of the mission is to solve the problem of “dark energy”, that is, why the expansion of the universe is accelerating.

Euclid follows ESA's previous cosmology mission, Planck. Between 2009 and 2013, the Planck telescope mapped cosmic background radiation and measured it with exceptional precision. Among other things, the results contributed to determining the properties of density fluctuations (“seeds of galaxies”) in the early universe and to shedding light on their origin. The final results from the Planck data were published in 2020.

The Euclid mission complements Planck in that, while Planck's primary research target was the early universe, the first 400,000 years, Euclid focuses on the later evolution of the universe.

The Euclid group at the University of Helsinki participates in the development of Euclid's data processing methods and the production of simulated data, and is responsible for Finland's Euclid data processing center. We have especially developed methods for calculating statistical quantities that describe the structure of the universe, such as correlation functions. After the launch, the Finnish Data Processing Center is responsible for processing 5% of Euclid's data. Euclid will be launched into space in July 2023.