Ultra High Energy Cosmic Rays: The theoretical challenge

Abstract

The origin of the highest-energy cosmic rays remains a mystery. The lack of a high energy cutoff in the cosmic ray spectrum together with an apparently isotropic distribution of arrival directions have strongly constrained most models proposed for the generation of these particles. An overview of the present state of theoretical proposals is presented. Astrophysical accelerators as well as top-down scenarios are reviewed along with their most general signatures. The origin and nature of these ultra-high energy particles will be tested by future observations and may indicate as well as constrain physics beyond the standard model of particle physics.

25 page review, 5 figs, to be published in the David Schramm Memorial Volume of Physics Reports, latex file; elsart

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Cited by in corpus (68)

• The Astrophysics of Ultrahigh Energy Cosmic Rays
• Neutrinos from propagation of ultra-high energy protons
• Planck-scale deformation of Lorentz symmetry as a solution to the UHECR and the TeV-$\gamma$ paradoxes
• Cosmic Rays from the Knee to the Highest Energies
• Ultra-High Energy Cosmic Ray Probes of Large Scale Structure and Magnetic Fields
• Ultra-High Energy Neutrino Fluxes and Their Constraints
• Limit on the diffuse flux of ultra-high energy tau neutrinos with the surface detector of the Pierre Auger Observatory
• Ultrahigh Energy Cosmic Rays: The state of the art before the Auger Observatory
• Plasma Wakefield Acceleration for Ultrahigh Energy Cosmic Rays
• Cosmogenic Neutrinos from Ultra-High Energy Nuclei
• Tracing protons through the Galactic magnetic field: a clue for charge composition of ultra-high energy cosmic rays
• Ultra-High Energy Cosmic Rays in a Structured and Magnetized Universe
• On the statistical significance of the GZK feature in the spectrum of ultra high energy cosmic rays
• Neutrino Clustering in Cold Dark Matter Halos : Implications for Ultra High Energy Cosmic Rays
• Neutrino Detection with Inclined Air Showers
• Point-like gamma ray sources as signatures of distant accelerators of ultra high energy cosmic rays
• Ultra-High Energy Cosmic Rays from Neutrino Emitting Acceleration Sources?
• Ultra-High Energy Cosmic Rays: A Probe of Physics and Astrophysics at Extreme Energies
• Cosmic Neutrinos and New Physics beyond the Electroweak Scale
• The GZK Feature in our Neighborhood of the Universe
• UHECR propagation in the Galaxy: clustering versus isotropy
• Determination of the calorimetric energy in extensive air showers
• Absolute Neutrino Mass Determination
• In Search for Extraterrestrial High Energy Neutrinos
• High Energy Physics in the Atmosphere: Phenomenology of Cosmic Ray Air Showers
• Strangelets as Cosmic Rays beyond the Greisen-Zatsepin-Kuzmin Cutoff
• Cosmic Rays and the Search for a Lorentz Invariance Violation
• Sensitivity of an underwater acoustic array to ultra-high energy neutrinos
• Cosmic Magnetic Fields and Their Influence on Ultra-High Energy Cosmic Ray Propagation
• Infrared and ultraviolet cutoffs of quantum field theory
• Energy-momentum uncertainties as possible origin of threshold anomalies in UHECR and TeV-gamma ray events
• Centaurus A as the Source of ultra-high energy cosmic rays?
• Astrophysical magnetic field reconstruction and spectroscopy with ultra high energy cosmic rays
• Large Scale Magnetic Fields and the Number of Cosmic Ray Sources above 10^(19) eV
• Constraints on the Acceleration of Ultra-High-Energy Cosmic Rays in Accretion-Induced Collapse Pulsars
• Propagation and Signatures of Ultra High Energy Cosmic Rays
• Extensive Air Showers from Ultra High Energy Gluinos
• Uncertainties in limits on TeV-gravity from neutrino-induced showers
• Inductive acceleration of UHECRs in sheared relativistic jets
• Have we already detected astrophysical symptoms of space-time noncommutativity ?
• Gamma-Ray Bursts and Magnetars as Possible Sources of Ultra High Energy Cosmic Rays: Correlation of Cosmic Ray Event Positions with IRAS Galaxies
• Gamma ray signatures of ultra high energy cosmic ray accelerators: electromagnetic cascade versus synchrotron radiation of secondary electrons
• Non-Critical Liouville String Escapes Constraints on Generic Models of Quantum Gravity
• Gravitational Larmor formula in higher dimensions
• The Enigma of the Highest Energy Particles of Nature
• Magnetic Monopoles with Wilson loops on a 5D Orbifold
• Clustering in Highest Energy Cosmic Rays: Physics or Statistics?
• Quantum Black Holes from Cosmic Rays
• Back-to-Back Black Holes decay Signature at Neutrino Observatories
• Magnetically Induced Anisotropies in the Arrival Directions of Ultra-high-energy Cosmic Rays from Nearby Radio Galaxies
• Particle Diffusion and Acceleration by Shock Wave in Magnetized Filamentary Turbulence
• Two-stage acceleration of interstellar ions due to the interaction of high-energy lepton plasma flow
• Ultra-High Energy Cosmic Ray Nuclei from Individual Magnetized Sources
• Hard component of ultra-high energy cosmic rays and vortons
• Magnetic Suppression of Cosmic Rays' Flux in $\mathbf{f}(\mathbf{R})$ and $\mathbf{f}(\mathbf{Q})$ Theories of Gravity
• A possible origin of superconducting currents in cosmic strings
• Astronomy with ultra high-energy particles
• Gravitational diffraction radiation
• Probing Physics at Extreme Energies with Cosmic Ultra-High Energy Radiation
• Seeking for the observational manifestation of de Sitter Relativity
• The Future of Ultra High Energy Cosmic Rays
• Ongoing Space Physics - Astrophysics Connections
• Simulation of up- and down-going neutrino induced showers at the site of the Pierre Auger Observatory
• On a mechanism of highest-energy cosmic ray acceleration
• Astroparticle Physics: The High Energy Tail of the Cosmic Ray Spectrum
• Ultra-high Energy Cosmic Rays: a probe into New Physics
• On the extragalactic jet asymmetry and composition, and the production of high energy cosmic rays
• Galactic Magnetic Field Structure and Ultra High Energy Cosmic Ray Propagation