Related papers: Cosmic Ray Positrons from Cosmic Strings
In light of the mounting evidence that the highest energy cosmic rays are dominated by protons and not gamma-rays, we discuss the prospect that these cosmic rays are generated in the decay or annihilation of superheavy relic particles. We…
Several cosmic ray experiments have measured the positron fraction up to few hundred GeV. Their data have revealed an excess of positrons above 10 GeV that is not consistent with the secondary production of these particles in the…
We compute spectra of particles produced during a dilaton-driven kinetic inflation phase within string cosmology models. The resulting spectra depend on the parameters of the model and on the type of particle and are quite varied, some…
The local interstellar spectrum of cosmic ray electrons and positrons from 0.8 GeV to 2 TeV is derived by demodulating the measured spectra by balloon and satellite experiments. It can be well represented by a single power law in kinetic…
We discuss the production of ultra high energy secondary protons by cosmic ray primary nuclei propagating in the intergalactic space through Cosmic Microwave Background (CMB) and Infrared (IR) radiations. Under the assumption that only…
We explore the possibility that Fast Radio Bursts are due to the annihilation of cusps on cosmic string loops. We compute the energy released in the annihilation events in the radio region, the expected event rate, and the time scale of the…
The supernova paradigm for the origin of galactic cosmic rays has been deeply affected by the development of the non-linear theory of particle acceleration at shock waves. Here we discuss the implications of applying such theory to the…
The highest energy cosmic rays could be produced by drifts in magnetized, cylindrically collimated, sheared jets of powerful active galaxies (i.e. FR II radiogalaxies; radio loud quasars and high power BL Lacs). We show that in such…
We study the effects that the diffusion of the cosmic rays in the magnetic field of the Local Supercluster can have on the spectrum of a nearby extragalactic source at ultrahigh energies. We find that the strong enhancement of the flux…
A new conceptual approach for examining the origin of cosmic rays is developed by considering the characteristics of particle trajectory distributions in four-dimensional Euclidean space-time. Transformation of an isotropic distribution…
We account for particle emission and gravitational radiation from cosmic string loops to determine their effect on the loop distribution and observational signatures of strings. The effect of particle emission is that the number density of…
Cosmic ray antiprotons provide a powerful tool to probe dark matter annihilations in our galaxy. The sensitivity of this important channel is, however, diluted by sizable uncertainties in the secondary antiproton background. In this work,…
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…
It is shown that the fusion of strings is a source of particle production in nucleus--nucleus collisions outside the kinematical limits of nucleon--nucleon collisions. This fact, together with another effect of string fusion, the reduction…
We calculate the gravitational radiation from a cusp of the chiral cosmic strings as a function of the current on the string in the limit of small values of the current. The smoothing of the cosmic string cusp due to the presence of the…
We calculate the gravitational radiation emitted by an infinite cosmic string with two oppositely moving wave-trains, in the small amplitude approximation. After comparing our result to the previously studied cases we extend the results to…
High energy (~GeV) positrons are seen within cosmic rays and observation of a narrow line at 511 keV shows that positrons are annihilating in the galaxy after slowing down to ~keV energies or less. Our state of knowledge of the origin of…
The electron and positron cosmic rays puzzle has triggered a revolution in the field of astroparticle physics. Many hypotheses have been proposed to explain the unexpected rise of the positron fraction, observed by HEAT and PAMELA…
We show that a tangle of light superconducting strings in the Milky Way could be the source of the observed 511 KeV emission from electron-positron annihilation in the Galactic bulge. The scenario predicts a flux that is in agreement with…
Ongoing experimental efforts to detect cosmic sources of high energy neutrinos are guided by the expectation that astrophysical accelerators of cosmic ray protons would also generate neutrinos through interactions with ambient matter and/or…