Correlation of Photon and Neutrino Fluxes in Blazars and Gamma Ray Bursts

Relativistic black-hole jet sources are leading candidates for high energy (>> TeV) neutrino production. The relations defining (a) efficient photopion losses of cosmic-ray protons on target photons and (b) gamma-gamma opacity of gamma rays through that same target photon field imply clear multiwavelength predictions for when and at what energies blazars and GRBs should be most neutrino bright and gamma-ray dim. The use of multiwavelength observations to test the standard relativistic jet model for these source is illustrated.