Related papers: Expected Signature For the Lorentz Invariance Viol…
We examine what the absorbed spectra of extra-galactic TeV gamma-ray sources, such as blazars, would look like in the presence of Lorentz invariance violation (LIV). Pair-production with the extra-galactic background light modifies the…
Lorentz invariance violation (LIV) introduced as a generic modification to particle dispersion relations can change the photon energy threshold of pair-production, which modifies the expected gamma-ray flux from astrophysical sources. In…
Lorentz invariance violation (LV) is examined through the time delay between high-energy and low-energy photons in gamma-ray bursts (GRBs). Previous studies determined the LV energy scale as $E_{\rm LV} \simeq 3.60 \times 10^{17}$~GeV using…
The positive-to-negative transition of spectral lag is an uncommon feature reported in a small number of GRBs. An application of such a feature has been made to constrain the critical quantum gravity energy ($E_{\rm QG}$) of the light…
The spectral lags of gamma-ray bursts (GRBs) have been viewed as the most promising probes of the possible violations of Lorentz invariance (LIV). However, these constraints usually depend on the assumption of the unknown intrinsic time lag…
It has been long conjectured that a signature of Quantum Gravity will be Lorentz Invariance Violation (LIV) that could be observed at energies much lower than the Planck scale. One possible signature of LIV is an energy-dependent speed of…
Very high-energy astrophysical gamma rays suffer a suppression of their flux along their propagation due to their interaction, through the $\gamma\gamma\to e^+e^-$ pair-production process, with the soft photon backgrounds present in the…
In this paper, we consider the impact of Lorentz Invariance Violation (LIV) on the $\gamma-\gamma$ opacity of the Universe to VHE-gamma rays, compared to the effect of local under-densities (voids) of the Extragalactic Background Light, and…
Lorentz invariance violation (LIV) has long been recognized as an observable low-energy signature of quantum gravity. In spite of a great effort to detect LIV effects, so far only lower bounds have been derived. The high energy photons from…
The Large High Altitude Air Shower Observatory~(LHAASO) reported observation of photons with energies above 10~TeV from gamma-ray burst GRB 221009A. A suggestion was proposed that this result may contradict our knowledge of special…
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…
We analyze the MeV/GeV emission from four bright Gamma-Ray Bursts (GRBs) observed by the Fermi-Large Area Telescope to produce robust, stringent constraints on a dependence of the speed of light in vacuo on the photon energy (vacuum…
The air shower array Carpet-3 detected a 300 TeV photon from the direction of GRB 221009A at 4536 s after the Fermi-GBM trigger for this event. If the association with this gamma-ray burst is real, it poses two puzzles. First, why was this…
We show that the GRB 221009A spectrum detected by LHAASO can be used to probe effects of quadratic subluminal Lorentz Invariance Violation (LIV) through the enhancement of the observed flux at the highest energies. In particular, we argue…
In quantum gravity, a foamy structure of space-time leads to Lorentz invariance violation (LIV). As the most energetic astrophysical processes in the Universe, gamma-ray bursts (GRBs) provide an effective way to probe quantum gravity…
Gamma-ray bursts (GRBs) are among the most potent probes of Lorentz invariance violation (LIV), offering direct constraints on the quantum gravity energy scale ($E_{\rm QG}$) based on observations of energy-dependent time lags. Individual…
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…
On October 9, 2022, the Large High Altitude Air Shower Observatory (LHAASO) reported the observation of the very early TeV afterglow of the brightest-of-all-time GRB 221009A, recording the highest photon statistics in the TeV band ever from…
Some Quantum Gravity (QG) theories allow for a violation of Lorentz invariance (LIV), manifesting as a dependence of the velocity of light in vacuum on its energy. If such a dependence exists, then photons of different energies emitted…
Lorentz-invariance violation (LV) at energy scales approaching the Planck regime serves as a critical probe for understanding quantum gravity phenomenology. Astrophysical observations of gamma-ray bursts (GRBs) present a promising avenue…