Related papers: Future limits on isotropic Lorentz violation in th…
Spectropolarimetry of distant sources of electromagnetic radiation at wavelengths ranging from infrared to ultraviolet are used to constrain Lorentz violation. A bound of 3x10^{-32} is placed on coefficients for Lorentz violation.
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…
In the electromagnetism of loop quantum gravity, two helicities of a photon have different phase velocities and group velocities, termed as "vacuum birefringence". Two novel phenomenons, "peak doubling" and "de-polarization", are expected…
A general method is presented to build all gauge-invariant terms in gauge field theories, including quantum electrodynamics and quantum chromodynamics. It is applied to two experiments, light-by-light scattering and deep inelastic…
High-energy neutrino astronomy will be capable of observing particles at both extremely high energies and over extremely long baselines. These features make such experiments highly sensitive to the effects of CPT and Lorentz violation. In…
We consider the radiation emitted by an ultrarelativistic charged particle moving in a magnetic field, in the presence of an additional Lorentz-violating interaction. In contrast with prior work, we treat a form of Lorentz violation that is…
Motivated by experimental indications of a significant presence of heavy nuclei in the cosmic ray flux at ultra high energies ($\gtrsim 10^{19} \eV$), we consider the effects of Planck scale suppressed Lorentz Invariance Violation (LIV) on…
Violations of Lorentz Invariance, a cornerstone of modern physics, are predicted by theories of quantum gravity and by extensions of General Relativity involving new vector or tensor fields. In the weak-field limit, such a violation would…
We show that estimates of the Lorentz symmetry violation extracted from ultra-high energy cosmic rays beyond the GZK cut-off set bounds on the parameters of a Lorentz-violating extension of the Standard Model. Moreover, we argue that…
Lorentz violation (LV) is predicted by some quantum gravity theories, where photon dispersion relation is modified, and the speed of light becomes energy-dependent. Consequently, it results in a tiny time delay between high energy photons…
Vacuum Cherenkov radiation is investigated in the Lorentz-violating Standard-Model Extension for isotropic dim-5 operators $\hat{m}$ and $\hat{a}^{\mu}$ in the fermion sector. Both the kinematics and dynamics of this process are analyzed by…
The relentless efforts of the physics community has not yet availed us the solution of how to unify the Quantum Mechanics with General Relativity, a puzzle that has engaged the minds of the physicists for almost a century. The insufficiency…
The preliminary detections of the gamma-ray burst 221009A up to 18 TeV by LHAASO and up to 251 TeV by Carpet 2 have been reported through Astronomer's Telegrams and Gamma-ray Coordination Network circulars. Since this burst is at redshift…
As a potential consequence of Lorentz invariance violation~(LIV), threshold anomalies open a window to study LIV. Recently the Large High Altitude Air Shower Observatory~(LHAASO) reported that more than 5000 photons from GRB 221009A have…
This article reviews the methods used to obtain a two-sided bound on isotropic modified Maxwell theory from experimental data of ultra high-energy cosmic rays in 2008. The bound is updated with results from the HEGRA experiment.
Despite the tremendous empirical success of equivalence principle, there are several theoretical motivations for existence of a preferred reference frame (or aether) in a consistent theory of quantum gravity. However, if quantum gravity had…
Relativistic Invariance might be modified by Quantum Gravity effects. The interesting point which emerged in the last fifteen years is that remnants of possible Lorentz Invariance Violations could be present at energies much lower than…
Tiny Lorentz Invariance Violation (LIV) effects, potentially arising from quantum gravity-induced spacetime structures, may also manifest in the proton sector, offering a plausible pathway to test Planck-scale physics through high-energy…
Gamma rays from TeV blazars have been detected by ground-based experiments for more than two decades. We have collected the most extensive set of archival spectra from these sources in order to constrain the processes affecting gamma-ray…
Cosmological limits on Lorentz invariance breaking in Chern-Simons $(3+1)-dimensional$ electrodynamics are used to place limits on torsion. Birefrigence phenomena is discussed by using extending the propagation equation to Riemann-Cartan…