Related papers: GZK photon constraints on Planck scale Lorentz vio…
Due to the high energies and long distances to the sources, astrophysical observations provide a unique opportunity to test possible signatures of Lorentz invariance violation (LIV). Superluminal LIV enables the decay of photons at high…
Owing to their isotropy, it is generally believed that ultrahigh energy cosmic rays (UHECRs) are extragalactic in origin. It is then expected that interactions of these cosmic rays with photons of the cosmic background radiation (CBR)…
Astrophysical tests of Planck-suppressed Lorentz violations had been extensively studied in recent years and very stringent constraints have been obtained within the framework of effective field theory. There are however still some…
We address several criticisms by Amelino-Camelia of our recent analyses of two observational constraints on Lorentz violation at order E/M_{Planck}. In particular, we emphasize the role of effective field theory in our analysis of…
Quantum photon effects in vacuum provide an interesting setting to test quantum electrodynamics, serving as a source for predictions about physics beyond the Standard Model. In this paper, we investigate these effects by calculating the…
We present new two-sided constraints on Lorentz Invariance violation energy scale for photons with quartic dispersion relation from recent gamma ray observations by Tibet-AS$\gamma$ and LHAASO experiments. The constraints are based on the…
In previous papers (e.g. physics/0003080 and references therein), it was pointed out that Lorentz symmetry violation (LSV) at Planck scale can play a crucial role in astrophysical processes at very high energy. It can potentially inhibit…
As a basic symmetry of Einstein's theory of special relativity, Lorentz invariance has withstood very strict tests. But there are still motivations for such tests. Firstly, many theories of quantum gravity suggest violations of Lorentz…
Due to the high energies and long distances involved, astrophysical observations provide a unique opportunity to test possible signatures of Lorentz Invariance Violation (LIV). Superluminal LIV enables the decay of photons at high energy…
Present and future ultra-high-energy-cosmic-ray facilities (e.g., the Pierre Auger Observatory with South and North components) and TeV-gamma-ray telescope arrays (e.g., HESS or VERITAS and CTA) have the potential to set stringent indirect…
A status report is given of some recent theoretical and experimental investigations looking for signals of Lorentz violation in QED. Experiments with light, charged particles, and atoms have exceptional sensitivity to small shifts in energy…
The clustering of ultra high energy cosmic ray events suggests that they have originated from compact sources. One of the possible physical mechanisms by which ultra high energy nuclei reach the Earth from far away astrophysical sources…
We correct the fitting formula used in refs. [1,2] to obtain a robust limit on a violation of Lorentz invariance that depends linearly on the photon energy. The correction leads to a slight increase of the limit on the scale of the…
It was recently proposed that a giant flare of the blazar PKS B1424-418 at redshift $z=1.522$ is in association with a PeV-energy neutrino event detected by IceCube. Based on this association we here suggest that the flight time difference…
Lorentz invariance is one of the fundamental tenets of Special Relativity, and has been extensively tested with laboratory and astrophysical observations. However, many quantum gravity models and theories beyond the Standard Model of…
It is not yet clear whether the observed flux suppression for ultra-high energy cosmic rays (UHECR) at energies above \simeq 4.10E19 eV is a signature of the Greisen-Zatsepin-Kuzmin (GZK) cutoff or corresponds, for instance, to the maximum…
The spontaneous breakdown of 4-dimensional Lorentz invariance in the framework of QED with the nonlinear vector potential constraint A_{\mu}^{2}=M^{2}(where M is a proposed scale of the Lorentz violation) is shown to manifest itself only as…
Some approaches to Quantum Gravity (QG) predict a modification of photon dispersion relations due to a breaking of Lorentz invariance. The effect is expected to affect photons near an effective QG energy scale. This scale has been…
It was recently suggested that possible small volations of Lorentz invariance could explain the existence of UHECR beyond the GZK cutoff and the observations of multi-TeV gamma-rays from Mkn 501. Our analysis of Lorentz-violating kinematics…
We briefly discuss the implications of recent AUGER results for patterns of Lorentz symmetry violation (LSV), assuming that the existence of the Greisen-Zatsepin-Kuzmin cutoff is definitely confirmed. The mass composition of the…