Identifying sources of high-energy neutrinos of the AGN type: A theoretical approach

Active galactic nuclei (AGN) have long been predicted to emit neutrinos if they host sites of cosmic-ray acceleration to very high energies. Until a few years ago neutrino astrophysics was merely a prediction by (some) cosmic-ray theorists. It became reality with the first discovery of an astrophysical neutrino flux ~7 years ago. Although the origin of these neutrinos remains unclear up to now, jets of AGN remain among the prime candidate sources.
In this presentation I will discuss the multimessenger approach in the framework of hadronic AGN emission models from a theoretical perspective. Special emphasis will be given on external target photon fields.