Related papers: Can high energy cosmic rays be vortons ?
Protons with energies up to 10^15 eV are the main component[1] of cosmic rays, but evidence for the specific locations where they could have been accelerated to these energies has been lacking[2]. Electrons are known to be accelerated to…
We present the main results on the energy spectrum and composition of the highest energy cosmic rays of energy exceeding 10$^{18}$ eV obtained by the High Resolution Fly's Eye and the Southern Auger Observatory. The current results are…
Ultrahigh energy cosmic rays that produce giant extensive showers of charged particles and photons when they interact in the Earth's atmosphere provide a unique tool to search for new physics. Of particular interest is the possibility of…
The interaction of cosmic rays with the gas contained in our Galaxy is a guaranteed source of diffuse high energy neutrinos. We provide expectations for this component by considering different assumptions for the cosmic ray distribution in…
Gamma-ray blazars are among the most extreme astrophysical sources, harboring phenomena far more energetic than those attainable by terrestrial accelerators. These galaxies are understood to be active galactic nuclei that are powered by…
The origin of ultra-high energy cosmic rays $($UHECRs$)$ remains a mystery. It has been suggested that UHECRs can be produced by the stochastic acceleration in relativistic jets of gamma-ray bursts $($GRBs$)$ at the early afterglow phase.…
Adopting the convection-diffusion model for energetic electron and proton propagation, and accounting for all the relevant hadronic and leptonic processes, the steady-state energy distributions of these particles in the starburst galaxies…
Nearby sources of cosmic rays up to a ZeV(=10^21 eV) could be observed with a multi-messenger approach including secondary gamma-rays and neutrinos. If cosmic rays above ~10^18 eV are produced in magnetized environments such as galaxy…
We demonstrate by numerical flux calculations that neutrino beams producing the observed highest energy cosmic rays by weak interactions with the relic neutrino background require a non-uniform distribution of sources. Such sources have to…
In this lecture I give an overview of shock acceleration, interactions of high energy cosmic rays with, and propagation through, the background radiation, and the resulting electron-photon cascade. I argue that while the origin of the…
We determine the probability that an ultrahigh energy (above 5\cdot 10^{19} eV) proton created at a distance r with energy E arrives at earth above a threshold E_c. The clustering of ultrahigh energy cosmic rays suggests that they might be…
Analytical calculations of extra-galactic cosmic ray spectra above ~10^17 eV are often performed assuming continuous source distributions, giving rise to spectra that depend little on the propagation mode, be it rectilinear or diffusive. We…
The runaway breakdown -- extensive atmospheric shower discharge (RB - EAS) excited in thunderstorm atmosphere by high energy cosmic ray particles ($\epsilon_p>10^{17} - 10^{19}$ eV) generate very powerful radio pulse. The RB - EAS theory is…
Recent measurements of ultra-high energy cosmic rays and neutrinos are briefly reviewed. With several new large scale observatories nearing completion or becoming fully operational only very recently, a large body of high quality and high…
Since their first observation in 1962, the existence of Ultra High Energy Cosmic Rays (UHECR) remains a mystery in modern astrophysics. Those cosmic rays, with energies well above 50 EeV ($50\times 10^{18}$eV), can hardly be accelerated,…
Cosmic rays are energetic charged particles from extraterrestrial sources, with the highest energy events thought to come from extragalactic sources. Their arrival is infrequent, so detection requires instruments with large collecting…
The recent detection of delayed, low energy emission from Gamma-Ray Burst (GRB) sources confirmed the cosmological origin of the bursts and provided support for models where GRBs are produced by the dissipation of the kinetic energy of…
Large-scale cosmic filaments connect galaxies, clusters and voids. They are permeated by magnetic fields with a variety of topologies. Cosmic rays with energies up to $10^{20}\;\!{\rm eV}$ can be produced in astrophysical environments…
The propagation of high-energy cosmic rays through giant molecular clouds constitutes a fundamental process in astronomy and astrophysics. The diffusion of cosmic-rays through these magnetically turbulent environments is often studied…
In General Relativity, there is a new field of activity concerning the study of charged stars. In a recent paper, Ray et al. have shown the possibility that the collapse of a charged star could form a charged black hole before all the…