Theoretical Astrophysics (TAP)

The Theoretical Astrophysics group at HITS seeks to understand the physics of cosmic structure formation over the last 13.5 billion years, from briefly after the Big Bang until today. The group is especially interested in how galaxies and stars form and aims to constrain the properties of dark matter and dark energy, the two enigmatic matter and energy components that dominate today’s cosmos. A prominent role in this work is played by numerical simulations on a variety of scales, both of the collisionless and the hydrodynamic type. To this end, group leader Volker Springel and his team members develop novel numerical schemes that can be used efficiently on very large super-computers with the goal of exploiting them in full to link the initial conditions of the universe with its complex evolved state today. The simulation models are indispensable for the interpretation of observational data and comparison of those data with theoretical models.

Recently, the TAP group developed the novel moving-mesh code AREPO, which offers significant advantages over previous simulation techniques used in cosmic structure formation. It combines the high accuracy of traditional Eulerian hydrodynamics with the automatic adaptivity and Galilean invariance of smoothed particle hydrodynamics. The application and further improvement of this new method has been one of the priorities in the group’s recent research.