Related papers: Ultra-high Energy Cosmic Rays: a probe into New Ph…
Interfaces between high-energy physics, astrophysics and cosmology are reviewed, with particular emphasis on the important roles played by high-energy cosmic-ray physics. These include the understanding of atmospheric neutrinos, the search…
The origin of Galactic cosmic rays (with energies up to 10^15 eV) remains unclear, though it is widely believed that they originate in the shock waves of expanding supernova remnants. Currently the best way to investigate their acceleration…
Cosmic ray (CR) particles arrive at the top of the Earth's atmosphere at a rate of around 1000 per square meter per second. They are mostly ionized nuclei - about 90% protons, 9% alpha particles traces of heavier nuclei and approximately 1%…
Suppose that even the highest energy cosmic rays (CRs) observed on Earth are protons accelerated in local Milky Way Galaxy sources, with few if any from more distant sources. In this paper we treat the problem that supernovae remnants…
Extragalactic astronomy with photons ends at ~0.1 PeV, but we know there are astrophysical sources for seven more decades of energy beyond this. To probe the highest energy sources and particles in the universe, new messengers, such as…
High-energy photons are a powerful probe for astrophysics and for fundamental physics under extreme conditions. During the recent years, our knowledge of the most violent phenomena in the Universe has impressively progressed thanks to the…
The primary cosmic rays particles with energies above 10**20 eV have been observed at many extensive air shower arrays since the beginning of observations over 40 years ago. The validity of measurements of signal s(600) used as energy…
It is now widely acknowledged that cosmic rays experiments can test possible new physics directly generated at the Planck scale or at some other fundamental scale. By studying particle properties at energies far beyond the reach of any…
The Pierre Auger Observatory has been detecting ultra-high energy cosmic rays (UHECRs) for more than fifteen years. An essential feature of the Observatory is its hybrid design: cosmic rays above $100~$PeV are detected through the…
One of the models recently proposed to explain the origin of the ultra high energy cosmic rays assumes that these particles may be accelerated by the electromotive force around presently inactive quasar remnants. We study predictions for…
Although cosmic rays were discovered over 100 years ago their origin remains uncertain. They have an energy spectrum that extends from 1 GeV to beyond 1020 eV, where the rate is less than 1 particle per km2 per century. Shortly after the…
Ultra-high-energy cosmic rays, accelerated hadrons that can exceed energies of $10^{20}$ eV, are the highest-energy particles ever observed. While the sources producing UHECRs are still unknown, the Pierre Auger Observatory has detected a…
Cosmic rays represent one of the most important energy transformation processes of the universe. They bring information about the surrounding universe, our galaxy, and very probably also the extragalactic space, at least at the highest…
Cosmic ray astronomy attempts to identify and study the sources of ultrahigh energy cosmic rays. It is unique in its reliance on charged particles as the information carriers. While no discrete source of ultrahigh energy cosmic rays has…
This article reviews the present status of high energy gamma-ray astronomy at energies above 30 MeV. Observations in the past decade using both space- and ground-based experiments have been primarily responsible for giving a tremendous…
The origin of highest energy cosmic rays is yet unknown. An appealing possibility is the so-called Z-burst scenario, in which a large fraction of these cosmic rays are decay products of Z bosons produced in the scattering of ultrahigh…
From direct observations of the longitudinal development of ultra-high energy air showers performed with the Pierre Auger Observatory, upper limits of 3.8%, 2.4%, 3.5% and 11.7% (at 95% c.l.) are obtained on the fraction of cosmic-ray…
The astrophysical neutrinos recently discovered by the IceCube neutrino telescope have the highest detected neutrino energies --- from TeV to PeV --- and travel the longest distances --- up to a few Gpc, the size of the observable Universe.…
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.…
The energy spectrum of cosmic rays between 10**16 eV and 10**18 eV, derived from measurements of the shower size (total number of charged particles) and the total muon number of extensive air showers by the KASCADE-Grande experiment, is…