Related papers: Cosmic ray strangelets
A model is introduced, in which the irregularity spectrum of the Galactic magnetic field beyond the dissipation length scale is first a Kolmogorov spectrum $k^{-5/3}$ at small scales $\lambda \, = \, 2 \pi/k$ with $k$ the wave-number, then…
Gamma-ray Astronomy studies cosmic accelerators through their electromagnetic radiation in the energy range between ~100 MeV and ~100 TeV. The present most sensitive observations in this energy band are performed, from space, by the Large…
It has been speculated that the recently detected ultra-high energy cosmic rays may originate from the decays of relic particles with mass of order $10^{12}$ GeV clustered in the halo of our Galaxy. This hypothesis can be tested through…
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…
The understanding of the nature of ultra-high-energy cosmic rays is one of the most intriguing open questions for current and future observatories. These particles are expected to be accelerated in extragalactic sources. Because of their…
Recent balloon-borne and satellite experiments have established new features in the behavior of the spectra of cosmic rays. An analysis of all the data showed that hardening of most abundant primary cosmic ray nuclei spectra with increasing…
More than 20 years ago, Glendenning, Kettner and Weber proposed the existence of stable white dwarfs with a core of strange quark matter. More recently, by studying radial modes, Alford, Harris and Sachdeva concluded instead that those…
The measurement of ultra-high energy cosmic rays is an unique way to study article interactions at energies which are well above the capability of current accelerators. Significant progress in this field has occurred during last years,…
We study spectra of the Ultra High Energy Cosmic Rays assuming primaries are protons and photons, and that their sources are extragalactic. We assume power low for the injection spectra and take into account the influence of cosmic…
Recent advances in measuring and interpreting cosmic rays from the spectral ankle to the highest energies are briefly reviewed. A knee of heavy primaries and an ankle of light primaries have been observed at about 10^{17} eV. The light…
Although cosmic rays were discovered 90 years ago, we do not know how and where they are accelerated. There is compelling evidence that the highest energy cosmic rays are extra-galactic -- they cannot be contained by our galaxy's magnetic…
In this review we discuss the important progress made in recent years towards understanding the experimental data on cosmic rays with energies $\agt 10^{19}$ eV. We begin with a brief survey of the available data, including a description of…
A quark model with running coupling and running strange quark mass, which is thermodynamically self-consistent at both high and lower densities, is presented and applied to study properties of strange quark matter and structure of compact…
The hypothesis is considered that the present Galactic cosmic ray spectrum is at present softer than its time average due to source intermittency. Measurements of muogenic nuclides underground could provide an independent measurement of the…
The possible existence of strange stars in the universe will help in the understanding of various properties of quantum chromodynamics, like asymptotic freedom and chiral symmetry restoration, which is otherwise very difficult to prove in…
Ultra-high energy cosmic ray experimental data are now of very good statistical significance even in the region of the expected GZK feature. The identification of their sources requires sophisticate analysis of their propagation in the…
The Alpha Magnetic Spectrometer (AMS-02), which is scheduled to be deployed onboard the International Space Station later this year, will be capable of measuring the composition and spectra of GeV-TeV cosmic rays with unprecedented…
The Z-burst mechanism invoked to explain ultra-high energy cosmic rays is severely constrained by measurements of the cosmic gamma-ray background by EGRET. We discuss the case of optically thick sources and show that jets and hot spots of…
We investigate the stability of stars with a density discontinuity between a high-density core and a very low density mantle. Previous work on "strange dwarfs" suggested that such a discontinuity could stabilize stars that would have been…
We study the streaming instability of GeV$-100~$GeV cosmic rays (CRs) and its damping in the turbulent interstellar medium (ISM). We find that the damping of streaming instability is dominated by ion-neutral collisional damping in weakly…