scholarly journals Predictions of Ultra-High Energy Cosmic Ray Propagation in the Context of Homogeneously Modified Special Relativity

Symmetry ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1961
Author(s):  
Marco Danilo Claudio Torri ◽  
Lorenzo Caccianiga ◽  
Armando di Matteo ◽  
Andrea Maino ◽  
Lino Miramonti
Keyword(s):  
Special Relativity ◽  
Lorentz Invariance ◽  
Cosmic Ray ◽  
High Energy ◽  
Ultra High Energy ◽  
Attenuation Length ◽  
High Energy Cosmic Rays ◽  
Invariance Violation ◽  
The Universe ◽  
Interaction Probability

Ultra high energy cosmic rays (UHECRs) may interact with photon backgrounds and thus the universe is opaque to their propagation. Many Lorentz Invariance Violation (LIV) theories predict a dilation of the expected horizon from which UHECRs can arrive to Earth, in some case even making the interaction probability negligible. In this work, we investigate this effect in the context of the LIV theory that goes by the name of Homogeneously Modified Special Relativity (HMSR). In this work, making use of a specifically modified version of the SimProp simulation program in order to account for the modifications introduced by the theory to the propagation of particles, the radius of the proton opacity horizon (GZK sphere), and the attenuation length for the photopion production process are simulated and the modifications of these quantities introduced by the theory are studied.

scholarly journals Relativity in cosmologically preferred frame and the UHECR paradox

BIBECHANA ◽  
2014 ◽  
Vol 11 ◽  
pp. 17-24
Author(s):  
Saroj Nepal
Keyword(s):  
Special Relativity ◽  
Rest Frame ◽  
Lorentz Invariance ◽  
Cosmic Ray ◽  
High Energy ◽  
Ultra High Energy ◽  
High Energy Cosmic Rays ◽  
Preferred Frame ◽  
Invariance Violation ◽  
The Universe

The Greisen-Zatsepin-Kuzmin (GZK) cutoff (5 × 1019eV) of special relativity in the observed ultra high energy cosmic rays (UHECR) spectrum is one of the most puzzling paradoxes in physics. Experimentally a number of cosmic ray events have been detected above this GZK limit which is known as UHECR paradox. We propose a resolution of this paradox through a modification of the relativistic kinematics keeping in mind that it should not lead to predictions different from those of special relativity in the well tested domains. It is shown that theoretical limit in UHECR spectrum can be explained in the framework of Lorentz invariance violation (LIV) theories which assume the existence of a preferred frame. The present paper proposes that the velocity of the solar system with respect to the rest frame of the universe plays a role in explaining the paradox. DOI: http://dx.doi.org/10.3126/bibechana.v11i0.10375   BIBECHANA 11(1) (2014) 17-24

ULTRA-HIGH-ENERGY COSMIC RAYS AND PLANCK-SUPPRESSED LORENTZ INVARIANCE VIOLATION

2009 ◽  
Vol 18 (10) ◽  
pp. 1621-1625
Author(s):  
LUCA MACCIONE ◽  
ANDREA M. TAYLOR ◽  
DAVID M. MATTINGLY ◽  
STEFANO LIBERATI
Keyword(s):  
Lorentz Invariance ◽  
Cosmic Ray ◽  
High Energy ◽  
Effective Field ◽  
Pierre Auger Observatory ◽  
Ultra High Energy ◽  
High Energy Cosmic Rays ◽  
Invariance Violation ◽  
Zero Vector ◽  
Theory Framework

We investigate the consequences of higher dimension Lorentz violating, CPT even kinetic operators that couple standard model fields to a non-zero vector field in an Effective Field Theory framework. Comparing the ultra-high energy cosmic ray spectrum reconstructed in the presence of such terms with data from the Pierre Auger Observatory allows us to establish stringent bounds on O(E/M Pl )2 suppressed violations of Lorentz invariance.

scholarly journals ULTRA HIGH ENERGY COSMIC RAYS: ORIGIN AND PROPAGATION

2010 ◽  
Vol 25 (18) ◽  
pp. 1467-1481 ◽  
Author(s):  
TODOR STANEV
Keyword(s):  
Cosmic Rays ◽  
Gamma Rays ◽  
Cosmic Ray ◽  
High Energy ◽  
Ultra High Energy ◽  
Ultrahigh Energy ◽  
High Energy Cosmic Rays ◽  
Astrophysical Objects ◽  
Ultrahigh Energy Cosmic Rays ◽  
The Universe

We introduce the highest energy cosmic rays and briefly review the powerful astrophysical objects where they could be accelerated. We then introduce the interactions of different cosmic ray particles with the photon fields of the Universe and the formation of the cosmic ray spectra observed at Earth. The last topic is the production of secondary gamma rays and neutrinos in the interactions of the ultrahigh energy cosmic rays.

scholarly journals Quantum Gravity Phenomenology Induced in the Propagation of UHECR, a Kinematical Solution in Finsler and Generalized Finsler Spacetime

Galaxies ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 103
Author(s):  
Marco Danilo Claudio Torri
Keyword(s):  
Quantum Gravity ◽  
Lorentz Invariance ◽  
High Energy ◽  
Lorentz Covariance ◽  
High Energy Cosmic Rays ◽  
Invariance Violation ◽  
Finsler Spacetime ◽  
Background Fields ◽  
General Geometry ◽  
The Universe

It is well-known that the universe is opaque to the propagation of Ultra-High-Energy Cosmic Rays (UHECRs) since these particles dissipate energy during their propagation interacting with the background fields present in the universe, mainly with the Cosmic Microwave Background (CMB) in the so-called GZK cut-off phenomenon. Some experimental evidence seems to hint at the possibility of a dilation of the GZK predicted opacity sphere. It is well-known that kinematical perturbations caused by supposed quantum gravity (QG) effects can modify the foreseen GZK opacity horizon. The introduction of Lorentz Invariance Violation can indeed reduce, and in some cases making negligible, the CMB-UHECRs interaction probability. In this work, we explore the effects induced by modified kinematics in the UHECR lightest component phenomenology from the QG perspective. We explore the possibility of a geometrical description of the massive fermions interaction with the supposed quantum structure of spacetime in order to introduce a Lorentz covariance modification. The kinematics are amended, modifying the dispersion relations of free particles in the context of a covariance-preserving framework. This spacetime description requires a more general geometry than the usual Riemannian one, indicating, for instance, the Finsler construction and the related generalized Finsler spacetime as ideal candidates. Finally we investigate the correlation between the magnitude of Lorentz covariance modification and the attenuation length of the photopion production process related to the GZK cut-off, demonstrating that the predicted opacity horizon can be dilated even in the context of a theory that does not require any privileged reference frame.

scholarly journals High energy cosmic ray interactions and UHECR composition problem

2019 ◽  
Vol 210 ◽  
pp. 02001
Author(s):  
Sergey Ostapchenko
Keyword(s):  
Experimental Data ◽  
Monte Carlo ◽  
Cosmic Rays ◽  
Cosmic Ray ◽  
High Energy ◽  
Ultra High Energy ◽  
Hadronic Interactions ◽  
High Energy Cosmic Rays ◽  
Cosmic Ray Interactions ◽  
Composition Problem

The differences between contemporary Monte Carlo generators of high energy hadronic interactions are discussed and their impact on the interpretation of experimental data on ultra-high energy cosmic rays (UHECRs) is studied. Key directions for further model improvements are outlined. The prospect for a coherent interpretation of the data in terms of the UHECR composition is investigated.

scholarly journals Cosmic ray transport and anisotropies to high energies

2015 ◽  
Vol 2 ◽  
pp. 39-44 ◽  
Author(s):  
P. L. Biermann ◽  
L. I. Caramete ◽  
A. Meli ◽  
B. N. Nath ◽  
E.-S. Seo ◽  
...  
Keyword(s):  
Cosmic Ray ◽  
High Energy ◽  
Wave Number ◽  
Ultra High Energy ◽  
Galactic Magnetic Field ◽  
Chemical Abundances ◽  
High Energy Cosmic Rays ◽  
High Energies ◽  
Isotropic Approximation ◽  
Galactic Cosmic Ray

Abstract. A model is introduced, in which the irregularity spectrum of the Galactic magnetic field beyond the dissipation length scale is first a Kolmogorov spectrum k-5/3 at small scales λ = 2 π/k with k the wave-number, then a saturation spectrum k-1, and finally a shock-dominated spectrum k-2 mostly in the halo/wind outside the Cosmic Ray disk. In an isotropic approximation such a model is consistent with the Interstellar Medium (ISM) data. With this model we discuss the Galactic Cosmic Ray (GCR) spectrum, as well as the extragalactic Ultra High Energy Cosmic Rays (UHECRs), their chemical abundances and anisotropies. UHECRs may include a proton component from many radio galaxies integrated over vast distances, visible already below 3 EeV.

Sign in / Sign up

Export Citation Format

Share Document