We study the Universe by modelling and interpreting the information from multiple messengers: electromagnetic radiation over many orders of magnitude in frequency, astrophysical neutrinos, cosmic rays, and gravitational waves. We study systems possessing high velocity outflows and magnetic turbulence, their properties and efficiency in leading to particle acceleration, the production of secondaries, the transport of these messengers, and detection on Earth. We also study probes of new physics and the dynamics of binary compact objects relevant for gravitational wave science, including high-precision computations necessary to maximize the discovery potential of future gravitational wave observatories such as the Einstein telescope.

We unify the expertise from plasma physics, particle physics, (magneto)hydrodynamics, and general relativity. Our methods include particle-in-cell techniques, global and spatially resolved radiation models involving the numerical treatment of coupled differential equations, test particle approaches, analytical techniques, simulations from first principles, turbulence and magnetic field diagnostics. In the area of gravitational waves, we use cutting-edge methods from particle physics — effective field theory and scattering amplitude techniques — which are now part of the state-of-the-art in waveform modelling.

There are many synergies with adjacent disciplines in astroparticle physics. For instance, with the goal of unveiling the dark universe, we study multi-messenger observations that can constrain the nature of dark matter and dark energy. We are also exploring the relevant physical processes in interstellar medium. Moreover, we are interested in the physics of large scale structures and the early universe, investigating what can we learn about inflation and phase transitions from the cosmic microwave background and gravitational wave observations. As part of our mission, we continuously develop and harvest synergies at the interfaces between astroparticle physics and other fields, such as astronomy, plasma and particle physics.