Related papers: Recent developments in cosmic ray physics
Galactic cosmic ray (CR) acceleration to the knee in the spectrum at a few PeV is only possible if the magnetic field ahead of a supernova remnant (SNR) shock is strongly amplified by CR escaping the SNR. A model formulated in terms of the…
The origin of the knee in cosmic ray spectrum remains to be an unsolved fundamental problem. There are various kinds of models which predict different break positions and the compositions of the knee. In this work, we suggest to use diffuse…
Laboratory experiments to explore plasma conditions and stimulated particle acceleration can illuminate aspects of the cosmic particle acceleration process. Here we discuss the cosmic-ray candidate source object variety, and what has been…
Nonlinear kinetic theory of cosmic ray (CR) acceleration in supernova remnants is employed to calculate CR spectra. The magnetic field in SNRs is assumed to be significantly amplified by the efficiently accelerating nuclear CR component. It…
The search for the origin of cosmic rays is a quest of almost a hundred years. A recent theoretical proposal gives quantitative predictions, which can be tested with data. Specifically, it has been suggested, that all cosmic rays can be…
A brief review about the chemical composition of cosmic rays in the energy range 10^15 < E < 10^20 eV is given. While there is convincing evidence for an increasingly heavier composition above the knee, no clear picture has emerged at the…
An overview is given on results from direct and indirect measurements of galactic cosmic rays. Their implications on the contemporary understanding of the origin of cosmic rays and the knee in their energy spectrum are discussed.
The observation of a small change in spectral slope, or 'knee' in the fluxes of cosmic rays near energies 10^15 eV has caused much speculation since its discovery over 40 years ago. The origin of this feature remains unknown. A small…
The origin of Galactic cosmic-ray ions has remained an enigma for almost a century. Although it has generally been thought that they are accelerated in the shock waves associated with powerful supernova explosions-for which there have been…
The origin of the highest energy cosmic rays is still unknown. The discovery of their sources will reveal the workings of the most energetic astrophysical accelerators in the universe. Current observations show a spectrum consistent with an…
Investigations of the origin of cosmic rays are presented. Different methods are discussed: studies of cosmic gamma rays of energy from 30 MeV to about 10^15 eV (since photons point to their places of origin), studies of the mass…
In the last two decades, different advances with extensive air shower (EAS) experiments have allowed to unveil several details about the composition and energy spectrum of galactic cosmic rays from some TeV up to several hundreds of PeV,…
Recent results from the KASCADE experiment on measurements of cosmic rays in the energy range of the knee are presented. Emphasis is placed on energy spectra of individual mass groups as obtained from an two-dimensional unfolding applied to…
The knee phenomenon of the cosmic ray spectrum, which plays an important role in studying the acceleration mechanism of cosmic rays, is still an unsolved mystery. We try to reconcile the knee spectra measured by ARGO-YBJ and Tibet-III. A…
The Galactic cosmic ray spectrum is a remarkably straight power law. Our current understanding is that the dominant sources that accelerate cosmic rays up to the knee ($3 \times 10^{15}$ eV) or perhaps even the ankle ($3 \times 10^{18}$…
We introduce neutrino astronomy from the observational fact that Nature accelerates protons and photons to energies in excess of 10^{20} and 10^{13} eV, respectively. Although the discovery of cosmic rays dates back close to a century, we…
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…
We discuss possible implications of a large interaction cross section between cosmic rays and dark matter particles due to new physics at the TeV scale. In particular, in models with extra dimensions and a low fundamental scale of gravity…
The main purpose of this work is to find the causes of the break of the cosmic ray spectrum at an energy of 3 PeV, which is called the knee. The solution of the problem is associated with the determination of the nuclear composition of…
The recent success of a proposal from some time ago to explain the spectrum of cosmic rays allows some strong conclusions to be made on the physics of supernovae: In the context of this specific proposal to explain the origin of cosmic…