Neutrinos from gamma ray bursts in the IceCube and ARA era

In this review I discuss the ultra-high energy neutrinos (UHEN) originated from cosmic-ray propagation (GZK neutrinos) and from Gamma Ray Bursts (GRBs), and discuss their detectability in kilometers scale detectors like ARA and IceCube. While GZK neutrinos are expected from cosmic ray interactions on the CMB, the GRB neutrinos depend on the physics inside the sources. GRBs are predicted to emit UHEN in the prompt and in the later 'after-glow' phase. I discuss the constraints on the hadronic component of GRBs derived from the search of four years of IceCube data for a prompt neutrino flux from gamma-ray bursts (GRBs) and more in general I present the results of the search for high-energy neutrinos interacting within the IceCube detector between 2010 and 2013.