相关论文: Do we observe fluctuation of cross section in cosm…
Cross section fluctuations in nuclear scattering are briefly reviewed in order to show the main important features. Then chaotic scattering is introduced by means of a very simple model. It is shown that chaoticity produces the same kind of…
It has been claimed by others that observed temporal correlations of terrestrial cloud cover with `the cosmic ray intensity' are causal. The possibility arises, therefore, of a connection between cosmic rays and Global Warming. If true, the…
Variability in gravitationally lensed quasars can be due to intrinsic fluctuations of the quasar or due to ``microlensing'' by compact objects along the line of sight. If disentangled from each other, microlens-induced variability can be…
Recently, the {\it{Fermi}} space telescope has discovered two large $\gamma$-ray emission regions, the so-called "Fermi bubbles", that extend up to $\sim 50^\circ$ above and below the Galactic center. The $\gamma$-ray emission from the…
We assess the fragmentation of strange quark matter in astrophysical events, showing that the application of statistical multifragmentation models suggests that most of the fragments (strangelets) should belong to an unstable baryon number…
Simulating the irradiation of planetary atmospheres by cosmic ray particles requires, among others, the ability to understand and to quantify the interactions of charged particles with planetary magnetic fields. Here we present a process…
In the first part of this review we discuss the basic observational features at the end of the cosmic ray energy spectrum. We also present there the main characteristics of each of the experiments involved in the detection of these…
The origin of various celestial phenomena have remained mysterious for conventional astrophysics. Therefore, alternative solutions should be considered, taking into account the involvement of unstable dark-matter particle candidates, such…
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…
I give a brief overview of cosmic ray physics, highlighting some key questions and how they will be addressed by new experiments.
Anomalies drive scientific discovery -- they are associated with the cutting edge of the research frontier, and thus typically exploit data in the low signal-to-noise regime. In astronomy, the prevalence of systematics --- both "known…
Phase resolved observations of planetary bodies allow us to understand the longitudinal and latitudinal variations that make each one unique. Rotational variations have been detected in several types of astronomical bodies beyond those of…
We study the spectrum and anisotropies of ultrahigh energy cosmic ray transient sources, accounting for the effects of their propagation through the turbulent extragalactic magnetic fields. We consider either bursting sources or sources…
We begin with a brief overview of highest-energy cosmic ray data, and the experiments which will perform neutrino astronomy. We then discuss two particle physics aspects of neutrinos. They are possible long-lifetime decay of the neutrino,…
Galactic cosmic ray transport relies on the existence of turbulence on scales comparable with the gyration radius of the particles and with wavenumber vector oriented along the local magnetic field. In the standard picture, in which…
The evolution of the spectrum of cosmological fluctuations from one cycle to the next is studied. It is pointed out that each cycle leads to a reddening of the spectrum. This opens up new ways to generate a scale-invariant spectrum of…
The heavens are full of neutrinos, but so far we have observed a small subset of those. Performing such observations and analyzing the data from them require a thorough understanding of neutrino interactions. In this short review, the…
Our purpose is to evaluate the rate of the maximum energy and the acceleration rate that cosmic rays acquire in the non-relativistic diffusive shock acceleration as it could apply during their lifetime in various astrophysical sites, where…
The study of the gamma-ray radiation produced by cosmic rays that escape their accelerators is of paramount importance for (at least) two reasons: first, the detection of those gamma-ray photons can serve to identify the sources of cosmic…
Astronomical or cosmological redshifts are an observable property of extragalactic objects and have historically been wholly attributed to the recessional velocity of that object. The question of other, or intrinsic, components of the…