相关论文: On non hadronic origin of high energy neutrinos
I give a brief discussion of possible sources of high energy neutrinos of astrophysical origin over the energy range from $\sim 10^{12}$ eV to $\sim 10^{25}$ eV. In particular I shall review predictions of the diffuse neutrino intensity.…
High-energy neutrinos are traditionally regarded as unambiguous signatures of hadronic cosmic rays in astrophysical environments. Here we show that TeV neutrinos can instead be produced by energetic electrons through purely electromagnetic…
We show that the observed fluxes, spectra and sky distributions of the high energy diffuse backgrounds of astronomical neutrinos, gamma rays and cosmic ray positrons satisfy simple relations expected from their common production in hadronic…
The diffuse background of very high energy extra-terrestrial neutrinos recently discovered with IceCube is compatible with that expected from cosmic ray interactions in the Galactic interstellar medium plus that expected from hadronic…
High energy neutrinos with energy typically greater than tens of thousands of GeV may originate from several astrophysical sources. The sources may include, for instance, our galaxy, the active centers of nearby galaxies, as well as…
The collisions between accelerated protons and the photons present in cosmos can be a main source of high-energy neutrinos (E \geq 10^6 GeV) of all flavors above the atmospheric neutrino background. I discuss here the possibility of…
Some of the proposed explanations for the origin of ultrahigh-energy cosmic rays invoke new sources of energetic photons (e.g., topological defects, relic particles, etc.). At high red shift, when the cosmic microwave background has a…
The intrinsic tau neutrino flux from cosmological and astrophysical sources has usually been considered negligible in comparison to the electron and muon neutrino fluxes. However, the inclusion of the tau neutrino component coming from…
Extragalactic background of high energy neutrinos arising from the interactions of cosmic ray protons with far-infrared extragalactic background radiation is calculated. The main assumption is that the cosmic ray spectrum at energies higher…
I give a brief critical review of the predicted intensity of diffuse high energy neutrinos of astrophysical origin over the energy range from 10^12 eV to 10^24 eV. Neutrinos from interactions of galactic cosmic rays with interstellar matter…
Gamma-Ray Bursts (GRBs) are expected to efficiently accelerate protons up to relativistic energies. High-energy photons can originate from decay of neutral pions produced by the interaction of these protons with the medium surrounding the…
Diffuse background of high energy neutrinos arising from interactions of cosmic ray protons with far infrared radiation background in extragalactic space is calculated. It is assumed that cosmic ray spectrum at superhigh energies has…
Starburst galaxies are $\gamma$-ray sources. Canonically, their emission is driven by hadronic cosmic rays (CRs) interacting with interstellar gas, forming $\gamma$-rays via the decay of neutral pions. Charged pions are also formed in this…
Recent astronomical observations reveal that Active Galactic Nuclei (AGN) are sources of high-energy radiation. For example, the Fermi-LAT and Hess telescopes have detected gamma-ray emissions from the cores of several types of AGN's. Even…
We discuss briefly the potential sources of high energy astrophysical neutrinos and show estimates of the neutrino fluxes that they can produce. A special attention is paid to the connection between the highest energy cosmic rays and…
Recently the Fermi-LAT data have revealed two gamma-ray emitting bubble-shaped structures at the Galactic center. If the observed gamma rays have hadronic origin (collisions of accelerated protons), the bubbles must emit high energy…
Neutrinos at energies ranging from sub-TeV to EeV from astrophysical sources can yield interesting physical information about fundamental interactions, about cosmic rays and about the nature of the sources and their environment. Gamma-ray…
In view of the observation by IceCube of high-energy astrophysical neutrinos, it is important to quantify the uncertainty in the background of atmospheric neutrinos. There are two sources of uncertainty, the imperfect knowledge of the…
Interactions of cosmic ray protons and nuclei in their sources and in the interstellar medium produce "hadronic" gamma-ray emission. Gamma-rays can also be of "leptonic" origin, i.e. originating from high-energy electrons accelerated…
The IceCube experiment has recently reported the first observation of high-energy cosmic neutrinos. Their origin is still unknown. In this paper, we investigate the possibility that they originate in active galaxies. We show that hadronic…