scholarly journals Cosmology and Cosmic Rays Propagation in the Relativity with a Preferred Frame

2021 ◽  
Author(s):  
Georgy I. Burde
Keyword(s):  
Cosmic Rays ◽  
Observational Data ◽  
Background Radiation ◽  
Lorentz Invariance ◽  
High Energy ◽  
Particle Dynamics ◽  
Cosmological Models ◽  
High Energy Cosmic Rays ◽  
Preferred Frame ◽  
Time Symmetry

In this chapter, cosmological models and the processes accompanying the propagation of the cosmic rays on cosmological scales are considered based on particle dynamics, electrodynamics and general relativity (GR) developed from the basic concepts of the ‘relativity with a preferred frame’. The ‘relativity with a preferred frame’, designed to reconcile the relativity principle with the existence of the cosmological preferred frame, incorporates the preferred frame at the fundamental level of special relativity (SR) while retaining the fundamental space-time symmetry which, in the standard SR, manifests itself as Lorentz invariance. The cosmological models based on the modified GR of the ‘relativity with a preferred frame’ allow us to explain the SNIa observational data without introducing the dark energy and also fit other observational data, in particular, the BAO data. Applying the theory to the photo pion-production and pair-production processes, accompanying the propagation of the Ultra-High Energy Cosmic Rays (UHECR) and gamma rays through the universal diffuse background radiation, shows that the modified particle dynamics, electrodynamics and GR lead to measurable signatures in the observed cosmic rays spectra which can provide an interpretation of some puzzling features found in the observational data. Other possible observational consequences of the theory, such as the birefringence of light propagating in vacuo and dispersion, are discussed.

scholarly journals Lorentz Violation by the Preferred Frame Effects and Cosmic and Gamma Ray Propagation

Galaxies ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 119
Author(s):  
Georgy I. Burde
Keyword(s):  
Gamma Ray ◽  
Background Radiation ◽  
Lorentz Invariance ◽  
High Energy ◽  
Particle Dynamics ◽  
Microwave Background ◽  
Extragalactic Background Light ◽  
Preferred Frame ◽  
Very High Energy ◽  
Energy Gamma

The ‘relativity with a preferred frame’, designed to reconcile the relativity principle with the existence of the cosmological preferred frame, incorporates the preferred frame at the level of special relativity (SR) while retaining the fundamental spacetime symmetry, which, in the standard SR, manifests itself as Lorentz invariance. In this paper, the processes, accompanying the propagation of cosmic rays and gamma rays through the background radiation from distant sources to Earth, are considered on the basis of particle dynamics and electromagnetic field dynamics developed within the framework of the ‘relativity with a preferred frame’. Applying the theory to the photopion-production and pair-production processes shows that the modified particle dynamics and electrodynamics lead to measurable signatures in the observed cosmic and gamma-ray spectra which can provide an interpretation of some puzzling features found in the observational data. Other processes responsible for gamma-ray attenuation are considered. It is found, in particular, that electromagnetic cascades, developing on cosmic microwave background and extragalactic background light, may be reduced or suppressed due to the preferred frame effects which should influence the shape of the very high-energy gamma-ray spectra. Other possible observational consequences of the theory, such as the birefringence of light propagating in vacuo and dispersion, are discussed.

scholarly journals QUANTUM GRAVITY PHENOMENOLOGY, LORENTZ INVARIANCE AND DISCRETENESS

2004 ◽  
Vol 19 (24) ◽  
pp. 1829-1840 ◽  
Author(s):  
FAY DOWKER ◽  
JOE HENSON ◽  
RAFAEL D. SORKIN
Keyword(s):  
Phase Space ◽  
Cosmic Rays ◽  
Quantum Gravity ◽  
Phenomenological Model ◽  
Lorentz Invariance ◽  
Minkowski Spacetime ◽  
High Energy ◽  
High Energy Cosmic Rays ◽  
Quantum Gravity Phenomenology ◽  
Massive Particles

Contrary to what is often stated, a fundamental spacetime discreteness need not contradict Lorentz invariance. A causal set's discreteness is in fact locally Lorentz invariant, and we recall the reasons why. For illustration, we introduce a phenomenological model of massive particles propagating in a Minkowski spacetime which arises from an underlying causal set. The particles undergo a Lorentz invariant diffusion in phase space, and we speculate on whether this could have any bearing on the origin of high energy cosmic rays.

scholarly journals SPONTANEOUS VIOLATION OF LORENTZ INVARIANCE AND ULTRA-HIGH ENERGY COSMIC RAYS

2003 ◽  
Vol 12 (07) ◽  
pp. 1279-1287 ◽  
Author(s):  
J. W. MOFFAT
Keyword(s):  
Cosmic Rays ◽  
Lorentz Invariance ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
High Energy ◽  
Spontaneous Breaking ◽  
Ultra High Energy ◽  
High Energy Cosmic Rays ◽  
High Energies ◽  
Local Lorentz Invariance

We propose that local Lorentz invariance is spontaneously violated at high energies, due to a nonvanishing vacuum expectation value of a vector field ϕμ, as a possible explanation of the observation of ultra-high energy cosmic rays with an energy above the GZK cutoff. Certain consequences of spontaneous breaking of Lorentz invariance in cosmology are discussed.

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

scholarly journals TESTING RELATIVITY AT HIGH ENERGIES USING SPACEBORNE DETECTORS

2007 ◽  
Vol 16 (12b) ◽  
pp. 2343-2355
Author(s):  
F. W. STECKER
Keyword(s):  
Cosmic Rays ◽  
Quantum Gravity ◽  
Background Radiation ◽  
Lorentz Invariance ◽  
Threshold Energy ◽  
High Energy ◽  
Ultrahigh Energy ◽  
Large Extra Dimension ◽  
Γ Ray ◽  
Ultrahigh Energy Cosmic Rays

The Gamma-Ray Large Area Space Telescope (GLAST), to be launched in the fall of 2007, will measure the spectra of distant extragalactic sources of high energy γ-rays, particularly active galactic nuclei and γ-ray bursts. GLAST can look for energy-dependent γ-ray propagation effects from such sources as a signal of Lorentz invariance violation (LIV). These sources should also exhibit the high energy cutoffs predicted to be the result of intergalactic annihilation interactions with low energy photons having a flux level as determined by various astronomical observations. Such annihilations result in electron–positron pair production above a threshold energy given by 2me in the center-of-momentum frame of the system, assuming Lorentz invariance. If Lorentz invariance is violated, this threshold can be significantly raised, changing the predicted absorption turnover in the observed spectrum of the sources. Stecker and Glashow have shown that the existence of such absorption features in the spectra of extragalactic sources puts constraints on LIV. Such constraints have important implications for some quantum gravity and large extra dimension models. Future spaceborne detectors dedicated to measuring γ-ray polarization can look for birefringence effects as a possible signal of loop quantum gravity. As shown by Coleman and Glashow, a much smaller amount of LIV has potential implications for possibly suppressing the "GZK cutoff" predicted to be caused by the interactions of cosmic rays having multijoule energies with photons of the 2.7 K cosmic background radiation in intergalactic space. Owing to the rarity of such ultrahigh energy cosmic rays, their spectra are best studied by a UV-sensitive satellite detector which looks down on a large volume of the Earth's atmosphere to study the nitrogen fluorescence tracks of giant air showers produced by these ultrahigh energy cosmic rays. We discuss here, in particular, a two-satellite mission called OWL, which would be suited for making such studies.

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