University of Geneva Department of Astronomy: A key product of Euclid will be the reconstruction of maps of dark matter over the last ten billion years. In order to produce these maps, which enable the determination of the cosmological properties of our Universe, the distance of billions of galaxies need to be measured. This crucial task is under the responsibility of astrophysicists at UNIGE-DA, who developed dedicated algorithms and analysis pipelines. These measurements will also shed light on the evolution of galaxies and black holes throughout the history of the Universe. In addition UNIGE-DA hosts one of the ten Euclid data centers, whose supercomputers will process the enormous volume of data produced by the Euclid mission.

Department of Theoretical Physics: Researchers at the University of Geneva (UniGe-DPT) have played a pivotal role in the Euclid project by providing guidance on its scientific objectives. They have made significant contributions to the development and validation of tools for predicting the performance of Euclid. Their research is primarily focused on utilizing the data collected by Euclid to gain further insights into the theory of gravity and to explore novel approaches for challenging Einstein's theory of General Relativity. UniGe-DPT scientists are also at the forefront of studying relativistic effects in cosmology and have devised methods to model and observe these effects using Euclid.

Hardware: The Department of Astronomy was the prime contractor of a mechanical shutter for one of the two scientific instruments, the VIS optical imager. This mechanism is a complex device that needs to work in a very cold environment (-160 C) with extreme reliability and precision. The first design made at UNIGE has been taken over, optimized and finalized by the Swiss industry partner APCO Technologies S.A., who has also been in charge of the manufacturing and testing.

Contact persons: DPT: martin.kunz@unige.ch and D-ASTRO: stephane.paltani@unige.ch