Related papers: On the non-thermal electron-to-proton ratio at cos…
We present the results of new calculations of the energy spectra of cosmic ray electrons, positrons and also positron fraction under assumption that both electrons and positrons are generated by the same Galactic sources, which accelerate…
Stochastic acceleration of electrons and protons by waves propagating parallel to the large scale magnetic fields of magnetized plasmas is studied with emphasis on the feasibility of accelerating particles from a thermal background to…
Recently, the PAMELA, FERMI, HESS, and ATIC instruments have discovered interesting spectral features in the positron to total electron ratio and in the total electronic component of cosmic rays at high energy. These observations are…
Clusters of galaxies are believed to be capable to accelerate protons at accretion shocks to energies exceeding 10^18 eV. At these energies, the losses caused by interactions of cosmic rays with photons of the Cosmic Microwave Background…
The distances that galactic cosmic ray electrons and positrons can travel are severely limited by energy losses to at most a few kiloparsec, thereby rendering the local spectrum very sensitive to the exact distribution of sources in our…
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…
The spectral shape of cosmic ray positrons and antiprotons has been accurately measured in the broad kinetic energy range 1-350 GeV. In the higher part of this range (E > 30 GeV) the e+ and pbar are both well described by power laws with…
We make the first observation-based calculation of the energy that goes into cosmic-ray protons versus cosmic ray electrons in shock acceleration during structure formation. We find a ratio of energy in cosmic ray protons to energy in…
We study a generic class of models for ultra-high energy cosmic ray (UHECR) phenomenology, in which the sources accelerate protons and nuclei with a power-law spectrum having the same index, but with different values for the maximum proton…
Using Leaky Box Model propagation calculations for H nuclei and a Monte Carlo diffusion propagation model for electrons, starting from specific source spectra, we have matched the observed LIS spectra of these cosmic rays measured by…
Energy densities of relativistic electrons and protons in extended galactic and intracluster regions are commonly determined from spectral radio and (rarely) $\gamma$-ray measurements. The time-independent particle spectral density…
The anomalous bump in the cosmic ray positron to electron ratio at $10 GeV$ can be explained as being a component from a point source that was originally harder than the primary electron background and degrades due to synchrotron and…
The rapid rise in the cosmic ray positron fraction above 10 GeV, as measured by PAMELA and AMS, suggests the existence of nearby primary sources of high energy positrons, such as pulsars or annihilating/decaying dark matter. In contrast,…
So far the only seemingly significant indication of a cosmological variation exists for the proton-to-electron mass ratio as stated by Reinhold et al. (2006). The measured indication of variation is based on the combined analysis of H2…
In a recent paper (Moskalenko et al., 2002), it has been shown that the flux of secondary cosmic ray (CR) antiprotons appears to be contradictory to measurements of secondary to primary nuclei ratios in cosmic rays when calculated in the…
A basic quantity in the characterization of relativistic particles is the proton-to-electron (p/e) energy density ratio. We derive a simple approximate expression suitable to estimate this quantity, U_p/U_e = (m_p/m_e)^(3-q)/2, valid when a…
Cosmic rays in the energy range $10^{18.0}$ - $10^{18.5}$ eV are thought to have a light, probably protonic, composition. To study their origin one can search for anisotropy in their arrival directions. Extragalactic cosmic rays should be…
The observed spectrum of Galactic cosmic rays has several exciting features such as the rise in the positron fraction above ~10 GeV of energy and the spectral hardening of protons and helium at ~300 GeV/nucleon of energy. The ATIC-2…
The Voyager spacecrafts have been measuring since 2012 the rates of electron and nuclei of the cosmic radiation beyond the solar cavity at a distance of more than $10^{13}$ $meters$ from the Earth. A record of unique and notable findings…
The antiproton-to-proton ratio in the cosmic-ray spectrum is a sensitive probe of new physics. Using recent measurements of the cosmic-ray antiproton and proton fluxes in the energy range of 1-1000 GeV, we study the contribution to the…