The Universal γ-Ray Flux, Grand Unified Theories, and Extragalactic Magnetic Field
نویسندگان
چکیده
The isotropic component of the γ-ray flux between 100MeV and 100EeV (10 eV) contains important information about the origin of highest energy cosmic rays and the extragalactic magnetic field (EGMF). Using numerical simulations of extragalactic cosmic and γ-ray propagation we show that an average fraction of ≃ 10% γ-rays in the total cosmic ray flux around 10EeV would imply both a non-acceleration origin of highest energy cosmic rays and a large scale EGMF < ∼ 10 −11 G. Proposed observatories for ultrahigh energy cosmic rays should be able to test this signature. PACS numbers: 98.70.Sa, 98.70.Vc, 98.80.Cq, 95.30.Cq
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