Related papers: Superstring Relics, Supersymmetric Fragmentation a…
The possibility that the Fermi scale is the only fundamental energy scale of Nature is under serious consideration at present, yet cosmic rays may already have provided direct evidence of new physics at a much higher scale. The recent…
In this paper we review the extragalactic propagation of ultrahigh energy cosmic-rays (UHECR). We present the different energy loss processes of protons and nuclei, and their expected influence on energy evolution of the UHECR spectrum and…
The study of the interactions of Cosmic Rays (CR's) with universal diffuse background radiation can provide very stringent tests of the validity of Special Relativity. The interactions we consider are the ones characterized by well defined…
We discuss candidates for trans-GZK cosmic rays observed in a variety of detectors. Three types of primaries are represented among the abstracts submitted to this meeting: neutrin os causing a Z-burst, protons arising from the decay of…
The status of the observations of Ultra High Energy Cosmic Rays will be reviewed, focusing on the the latest results of HiRes and Auger observatories. A comprehensive analytical computation scheme to compute the expected UHECR spectrum on…
I will briefly review the formation and evolution of cosmic superstrings, in the context of brane-world cosmological models within M-theory. These objects can play the role of cosmic strings, offering a variety of astrophysical…
Super Heavy quasi-stable particles are naturally produced in the early universe and could represent a substantial fraction of the Dark Matter: the so-called Super Heavy Dark Matter (SHDM). The decay of SHDM represents also a possible source…
We describe features that could be observed in the line spectra of relic cosmological particles should quantum nonequilibrium be preserved in their statistics. According to our arguments, these features would represent a significant…
We demonstrate that if the universe is dominated by the massive cold dark matter, then besides the generally believed thermal distribution of the dark matter relics, there may exist some very energetic non-thermal relics of the dark matter…
From theoretical point of view and not being in contradiction with current observational data, the cosmic strings should have fundamentally different origin and are characterized by wide range of energies. The paper is devoted to search for…
We present a brief introduction to the physics of Ultra High Energy Cosmic Rays (UHECRs), concentrating on the experimental results obtained so far and on what, from these results, can be inferred about the sources of UHECRs.
We show that metastable cosmic strings break at early times, either via finite-temperature effects or by attaching to pre-existing monopoles during network percolation. The resulting segments can be initially super-horizon in size and thus…
We explore cosmological implications of dark matter as massive particles trapped on a brane embedded in a Randall-Sundrum noncompact higher dimension $AdS_5$ space. It is an unavoidable consequence of this cosmology that massive particles…
A larger Planck scale during an early epoch leads to a smaller Hubble rate, which is the measure for efficiency of primordial processes. The resulting slower cosmic tempo can accommodate alternative cosmological histories. We consider this…
We review the cosmology induced by finite temperature and quantum effects on non-supersymmetric string models. We show the evolution is attracted to radiation-like solutions after the Hagedorn era and before the electroweak phase…
We review the basic ideas on the origin of cosmic rays with energy in excess of $\sim 10^{19}$ eV, in the light of the most recent observational findings. The limited statistics of events detected by the two largest experiments currently…
The source of Ultra High Energy Cosmic Rays (UHECR) is still an unresolved mystery. Up until recently, sources of Gamma Ray Bursts (GRBs) had been considered as a suitable source for UHECR. Within the fireball model, the UHECR produced at…
According to recent conjectures on the existence of large extra dimensions in our universe, black holes may be produced during the interaction of Ultra High Energy Cosmic Rays with the atmosphere. However, and so far, the proposed…
We discuss possible ways to observationally detect the superdense cosmic objects composed of hypothetical sub-constituent fermions beneath the quark/lepton level, recently proposed by us. The characteristic mass and size of such objects…
We investigate the contribution made by small loops from a cosmic string network as seeds for large-scale structure formation. We show that cosmic string loops are highly correlated with the long-string network on large scales and therefore…