Institute for Advanced Study Astrophysics Seminar

I will review the recent "ultra-bright" GRB 130427A data and the puzzles (as well as non-puzzles) raised by its intepretation both in terms of the standard model and in terms of previous plausible extensions of this model. I then discuss the implications of the Icecube TeV neutrino non-detection of either this particular burst nor, so far, of the expected cumulative diffuse flux from many bursts, in terms of the standard model and the extended-standard model of the prompt emission, including photospheric and hadronic models. This is followed by a general discussion of the physics and issues behind the introduction of such extensions of the model, which have been motivated by the need to address the prompt gamma-ray spectra.