The main research field of Tim Schrabback is observational cosmology. Together with his research group he is analysing large astronomical data sets in order to probe the cosmological model and improve our understanding of astrophysical effects in galaxies and galaxy clusters.
As a primary astrophysical tool the group makes use of weak gravitational lensing. This effect describes subtle image distortions which get imprinted onto the observed shapes of background galaxies when their light bundles pass through the gravitational potential of the foreground matter distribution. By analysing these distortions it is possible to reconstruct the foreground mass distribution, which is dominated by the invisible dark matter. Such analyses also yield key constraints regarding the physical nature of dark energy, which has been introduced to account for the apparent accelerated expansion of the Universe.
In addition to contributing to the KiDS, SPT, eROSITA and Euclid collaborations, the research group is analysing new weak lensing follow-up observations of distant galaxy clusters obtained with ESO's VLT.