AT seminar on 6 October 2017 by Shigeru Yoshida
The IceCube Neutrino Observatory has revealed the bulk of high energy cosmic neutrinos at TeV and PeV energies as well as set the strong constraints on neutrino fluxes at EeV energies. As neutrino emissions are expected to be associated with high energy cosmic ray radiation, these neutrino observations present rich implications on yet-unknown origin of ultra-high energy cosmic rays (UHECRs). In this talk we review the recent observations of high energy neutrinos by IceCube, followed by discussions about their connections to characteristics of UHECR sources with minimum assumptions. The relations between the UHECR fluxes measured by the various airshower experiments, TeV-PeV energy neutrino flux detected by IceCube, and the upper limit of EeV energy neutrinos set by IceCube and Auger give genetic constraints on sources and compositions of UHECRs. Finally we describe an "unified model" to account all the UHECR and neutrino emissions and discuss if any known astronomical objects can be such sources-of-everything.