2002/08/31 by Jorge Alfaro, Gonzalo A. Palma, Gonzalo Palma · 2 citations
Physics and Astronomy · #Active galactic nucleus #Astronomy #Astrophysics #Black Holes and Theoretical Physics #Cosmic ray #Cosmology and Gravitation Theories #Cutoff #Energy spectrum #Flux (metallurgy) #Galaxy #Gravitation #Noncommutative and Quantum Gravity Theories #Physics #Quantum #Quantum gravity #Quantum mechanics #Ultra-high-energy cosmic ray #hep-th
paper · pdf · doi:10.1103/physrevd.67.083003
published as Phys.Rev. D67 (2003) 083003 · 18 pages, latex, 4 figures
arxiv created 2003/01/31 · openalex publication_date 2003/04/28 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
There are two main sets of data for the observed spectrum of ultrahigh energy cosmic rays (those cosmic rays with energies greater than \ensuremath∼4\ifmmode×\else\texttimes\fi1018 eV), the high resolution Fly's Eye (HiRes) Collaboration group observations, which seem to be consistent with the predicted theoretical spectrum (and therefore with the theoretical limit known as the Greisen-Zatsepin-Kuzmin cutoff), and the observations from the Akeno Giant Air Shower Array (AGASA) Collaboration group, which reveal an abundant flux of incoming particles with energies above 1\ifmmode×\else\texttimes\fi1020 eV, violating the Greisen-Zatsepin-Kuzmin cutoff. As an explanation of this anomaly it has been suggested that quantum-gravitational effects may be playing a decisive role in the propagation of ultrahigh energy cosmic rays. In this article we take the loop quantum gravity approach. We shall provide some techniques to establish and analyze new constraints on the loop quantum gravity parameters arising from both sets of data, HiRes and AGASA. We shall also study their effects on the predicted spectrum for ultrahigh energy cosmic rays. As a result we will state the possibility of reconciling the AGASA observations.