Our group does research in the field of astroparticle physics with neutrinos and is a member of an international collaboration that built and operates the IceCube Neutrino Observatory at the South Pole. The work of our group is broad and includes
Furthermore, we are involved in a cooperation with geophysics in the investigation of seismic influences at the Einstein Telescope, a third generation gravitational wave detector.
Below you will find some information about cosmic neutrinos and their relation to cosmic rays and gravitational waves.
The sources of ultrahigh-energy radiation (protons and heavier nuclei) have puzzled us for more than a century. The measured energies of these charged particles show that there must be objects in the universe that can accelerate particles to up to 10 million times the energy of the most powerful terrestrial accelerators such as the LHC at CERN. However, the identity of these sources and how they work are still largely unknown because the charged particles are deflected by cosmic magnetic fields and thus cannot be traced back to their origin. The identification and investigation of these energetic objects (candidates include active galactic nuclei, supernova remnants, and neutron star mergers) represents one of the central fields of research in astroparticle physics.
Unlike cosmic rays, neutrinos are electrically neutral and can therefore be traced directly to their source. They also interact only weakly and thus reach us even from very large distances and from dense sources. However, these properties also pose a great challenge for their detection. This is done indirectly by detecting the Cherenkov light produced by charged particles generated in neutrino reactions. In order to detect neutrinos or Cherenkov light, detectors with a very large instrumented volume of a transparent medium (e.g. water or ice) are required due to the low probability of alternation. One of these detectors is the IceCube Neutrino Observatory in the Antarctic ice at the geographic South Pole.
Gravitational waves are ripples in the fabric of spacetime, generated by some of the most violent and energetic processes in the universe, such as collisions between black holes or neutron stars. The detection of these waves is a groundbreaking achievement in astrophysics, opening up a new window for observing the cosmos. Unlike electromagnetic radiation (like light), gravitational waves are not impeded by matter, allowing us to peer into regions of space that were previously hidden and to observe events that occurred in the very early universe.
The detection of gravitational waves is crucial because it provides a new method for studying astronomical phenomena. It allows scientists to test Einstein's theory of general relativity under extreme conditions, study black holes and neutron stars in detail, and improve our understanding of the fundamental laws of physics. Gravitational waves can also provide insights into the rate of expansion of the universe and the nature of dark matter.
