ar X iv : a st ro - p h / 98 11 26 8 v 1 1 7 N ov 1 99 8 1 Ultra High Energy Cosmic Rays
نویسنده
چکیده
Ultra High Energy Cosmic Rays (UHECR) can be a signal from very early (post-infationary) Universe. At this cosmological epoch Topological Defects (TD) and long lived superheavy (SH) particles are expected to be naturally and effectively produced. Both of these relics can produce now the particles, such as protons and photons, with energies in a great excess of what is observed in UHECR, E ∼ 10 10 − 10 11 GeV. The Topological Defects as the UHECR sources are critically reviewed and cosmic necklaces and monopolonia are identified as most plausible sources. The relic superheavy particles and monopolonia are shown to be clustering in the halo of our Galaxy and their decays produce UHECR without GZK cutoff. The observational signatures of both models are discussed.
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