2003/09/29 by Robin Booth, Booth, Robin
Physics and Astronomy · #Astrophysics (astro-ph) #Astrophysics and Cosmic Phenomena #Cosmology and Gravitation Theories #FOS: Physical sciences #Particle physics theoretical and experimental studies #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0309803
arxiv created 2003/09/29 · openalex publication_date 2003/09/29 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A prediction of standard Big Bang cosmology is that the observed UHECR\n(ultra-high-energy cosmic rays) spectrum will exhibit a cutoff at the GKZ\nlimit, resulting from interaction with the photons that constitute the cosmic\nmicrowave background. We show that for the Quasi-Static Universe (QSU) model,\nin which photon energy is an invariant in the cosmological reference frame, the\nphoton number density in the universe today is a factor of 109 less than in\nthe standard model. As a consequence, the mean free path of UHECRs will exceed\nthe horizon distance of the universe, rendering it essentially transparent to\nUHECRs. The QSU model therefore predicts that no cutoff will be observed in the\nUHECR spectrum.\n