High energy astrophysical processes
  We briefly review the high energy astrophysical processes that are related to the production of high energy $\gamma$-ray and neutrino signals and are likely to be important for the energy loss of high and ultrahigh energy cosmic rays. We also give examples for neutrino fluxes generated by different astrophysical objects and describe the cosmological link provided by cosmogenic neutrinos. 
Todor Stanev