Markus Tobias Ahlers

Primary fields of research

Markus's research area is centered around high-energy astroparticle physics. He is interested in the puzzling phenomena of cosmic rays, gamma rays, and neutrinos and how these observations are related in the context of multi-messenger astronomy. A central theme in Markus's research is the study of transport phenomena of cosmic rays. These are essential for the interpretation of multi-messenger observations in terms of astrophysical processes. Inelastic interactions of high energy cosmic rays with cosmic radiation backgrounds or gas provide secondary fluxes of gamma rays and neutrinos that can help to identify the sources of cosmic rays. Elastic scattering of low energy cosmic rays with cosmic magnetic fields can be studied by the anisotropy of arrival directions of cosmic rays which serve as a probe of Galactic and extragalactic environments.

Markus is a member of the IceCube collaboration since 2007. He has been involved in IceCube analyses of neutrino emission from gamma-ray burst and the anisotropy in arrival directions of Galactic cosmic rays. He is very excited about the recently observed flux of high-energy neutrinos and how their unknown origin can be addressed via multi-messenger relations. Markus has also been studying possibilities to utilize neutrino telescopes as a probe of physics beyond the Standard Model. Rare interactions of neutrinos can be visible in neutrino telescopes due to the ultra-long baselines of neutrino propagation and the excellent background rejection.