Related papers: Superluminal Matter and High-Energy Cosmic Rays
The origin of the ultra high energy cosmic rays via annihilation of heavy stable, fermions "f", of the cosmological dark matter (DM) is studied. The particles in question are supposed to be created by the scalaron decays in $R^2$ modified…
It has been argued that the observations of cosmic particles with energies in excess of $10^8$ TeV represent a puzzle. Its solution requires new astrophysics or new particle physics. We show that the latter is unlikely given that the scale…
Since more than a century we investigate cosmic particles coming from the Universe with the aim of understanding their nature, their origin and how they are accelerated. So far, cosmic rays have provided many impressive results, giving…
The observation of twenty cosmic-ray air-showers at and above 10^{20} eV poses fascinating problems for particle astrophysics: how the primary particles are accelerated to these energies, how the primaries get here through the 2.7K…
This white paper was submitted to the US Astronomy and Astrophysics Decadal Survey (Astro2020) and defines the science questions to be answered in the next decade in the field of Ultra-High Energy Cosmic-Rays. Following a review of the…
These lectures discuss the mysteries involving the production and extragalactic propagation of ultrahigh energy cosmic rays and suggested possible solutions.
Candidate astrophysical acceleration sites capable of producing the highest energy cosmic rays (E > 10^{19.5} eV) appear to be at far greater distances than is compatible with their being known particles. The properties of a new particle…
Recent measurements of the properties of cosmic rays above 10^17 eV are summarized and implications on our contemporary understanding of their origin are discussed. Cosmic rays with energies exceeding 10^20 eV have been measured, they are…
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…
Very recently, a possible clustering of a subset of observed ultrahigh energy cosmic rays above about 40EeV (4x10^19eV) in pairs near the supergalactic plane was reported. We show that a confirmation of this effect would provide information…
Observations of cosmic rays have been improving at all energies, with higher statistics and reduced systematics. Fundamental questions remain regarding the origins of cosmic rays both within the Galaxy and in extragalactic sources, and new…
Several of the models for origin of the highest energy cosmic rays also predict significant neutrino fluxes. A common factor of the models is that they must provide sufficient power to supply the observed energy in the extragalactic…
We discuss theoretical issues and experimental data that brought the ultra high energy cosmic rays in the list of Nature's greatest puzzles. After many years of research we still do not know how astrophysical acceleration processes can…
Cosmic-rays with energies exceeding 10^{19} eV are referred to as Ultra High Energy Cosmic Rays (UHECRs). The sources of these particles and their acceleration mechanism are unknown, and for many years have been the issue of much debate.…
Cosmic ray particles with energies in excess of 10**(20) eV have been detected. The sources as well as the physical mechanism(s) responsible for endowing cosmic ray particles with such enormous energies are unknown. This report gives a…
The surprising lack of a high energy cutoff in the cosmic ray spectrum at the highest energies together with an apparently isotropic distribution of arrival directions have strongly challenged most models proposed for the acceleration of…
The field of high energy particle astronomy is exciting and rapidly developing. In the last few years, we have detected extragalactic sources of intense TeV gamma radiation and individual cosmic ray particles with energies exceeding 25…
We discuss the most recent developments in our understanding of the acceleration and propagation of cosmic rays up to the highest energies. In particular we specialize our discussion to three issues: 1) developments in the theory of…
Super-high energy corpuscular and gamma rays as well as cosmic high--power density sources are hard to explain in a galaxy model framework. Attempts to include some of those phenomena in the Standard Cosmological Model also encounter…
This is a written version of a series of lectures aimed at graduate students in astrophysics/particle theory/particle experiment. In the first part, we explain the important progress made in recent years towards understanding the…